• Imaging Science in Dentistry
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• 제30권2호
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• pp.127-131
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• 2000

A 19-year-old man was referred to Seoul National University Dental Hospital for evaluation of a large painless swelling of the left mandibular angle area in August, 1999. The growth had been first noted 6 years ago. He had visited other hospital in 1997. In spite of the treatment given at the hospital, the mass continued to grow rapidly. Conventional radiographs in 1999 showed an expansile, lobulated, and destructive lesion of the left mandibular body. CT scan demonstrated an expansile mass with a corticated margin. Bony septa were seen within the lesion. Internal calcification noted on the bone-setting CT image, and corresponded to the hypointense area in T1-weighted MRI image. MRI clearly delineated the extent of the lesion which had heterogenous intermediate signal intensity in T1-weighted images and heterogenous hyperintense signal intensity in T2-weighted images. The lesion was well-enhanced. Histopathologically, the lesion was well demarcated. Multinucleated giant cells were presented in a fibrous background, demonstrating a storiform pattern. Areas of osteoid rimmed by a few osteoblasts were scattered throughout the lesion. Inflammatory cells, blood vessels, and hemosiderin deposition were also shown. CGCG may show lots of internal calcification foci on the CT, and varied signal intensity in MRI. More cases will be needed to understand the features of the CT & MR finding of CGCG.

• Corrosion Science and Technology
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• 제15권3호
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• pp.120-124
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• 2016

The effect of alloying element Ca (0, 1, and 2 wt%) on corrosion resistance and bioactivity of the as-received and anodized surface of rolled plate AM60 alloys was investigated. A plasma electrolytic oxidation (PEO) was carried out to form anodic oxide film in $0.5mol\;dm^{-3}\;Na_3PO_4$ solution. The corrosion behavior was studied by polarization measurements while the in vitro bioactivity was tested by soaking the specimens in Simulated Body Fluid (1.5xSBF). Optical micrograph and elemental analysis of the substrate surfaces indicated that the number of intermetallic particles increased with Ca content in the alloys owing to the formation of a new phase $Al_2Ca$. The corrosion resistance of AM60 specimens improved only slightly by alloying with 2 wt% Ca which was attributed to the reticular distribution of $Al_2Ca$ phase existed in the alloy that might became barrier for corrosion propagation across grain boundaries. Corrosion resistance of the three alloys was significantly improved by coating the substrates with anodic oxide film formed by PEO. The film mainly composed of magnesium phosphate with thickness in the range $30-40{\mu}m$. The heat resistant phase of $Al_2Ca$ was believed to retard the plasma discharge during anodization and, hence, decreased the film thickness of Ca-containing alloys. The highest apatite forming ability in 1.5xSBF was observed for AM60-1Ca specimens (both substrate and anodized) that exhibited more degradation than the other two alloys as indicated by surface observation. The increase of surface roughness and the degree of supersaturation of 1.5xSBF due to dissolution of Mg ions from the substrate surface or the release of film compounds from the anodized surface are important factors to enhance deposition of Ca-P compound on the specimen surfaces.

• 대한치과교정학회지
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• 제44권5호
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• pp.246-253
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• 2014

Objective: To evaluate the bioactivity, and the biomechanical and bone-regenerative properties of Ti6Al4V miniscrews subjected to anodization, cyclic precalcification, and heat treatment (APH treatment) and their potential clinical use. Methods: The surfaces of Ti6Al4V alloys were modified by APH treatment. Bioactivity was assessed after immersion in simulated body fluid for 3 days. The hydrophilicity and the roughness of APH-treated surfaces were compared with those of untreated (UT) and anodized and heat-treated (AH) samples. For in vivo tests, 32 miniscrews (16 UT and 16 APH) were inserted into 16 Wistar rats, one UT and one APH-treated miniscrew in either tibia. The miniscrews were extracted after 3 and 6 weeks and their osseointegration (n = 8 for each time point and group) was investigated by surface and histological analyses and removal torque measurements. Results: APH treatment formed a dense surface array of nanotubular TiO2 layer covered with a compact apatite-like film. APH-treated samples showed better bioactivity and biocompatibility compared with UT and AH samples. In vivo, APH-treated miniscrews showed higher removal torque and bone-to-implant contact than did UT miniscrews, after both 3 and 6 weeks (p < 0.05). Also, early deposition of densely mineralized bone around APH-treated miniscrews was observed, implying good bonding to the treated surface. Conclusions: APH treatment enhanced the bioactivity, and the biomechanical and bone regenerative properties of the Ti6Al4V alloy miniscrews. The enhanced initial stability afforded should be valuable in orthodontic applications.

• Journal of Periodontal and Implant Science
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• 제33권4호
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• pp.729-738
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• 2003

Nicotine is one of the major components of cigarette smoking which causes various systemic and local diseases to human body. The purpose of the present study was to investigate the effects of nicotine on bone mineralization in human fetal osteoblasts cell line(hFOB1). To compare the alkaline ph-osphatase(ALP) synthesis, hFOBl were cultured with DMEM/F-12 1:1 Mixture and 100 pg/ml, 1 ng/ml, 10 ng/ml, 100 ng/ml, 1 ${\mu}g$/ml, 10 ${\mu}g$/ml, 100 ${\mu}g$/ml of nicotine. And to compare the calcium accumulation, hFOB1 cultured for 23 days were quantified and photographed. ALP activity of hFOB1 exposed to nicotine was not significantly changed at a lower concentrations of nicotine, but was significantly decreased at a higher concentrations (10 ${\mu}g$/ml, 100 ${\mu}g$/ml) of nicotine (p<0.05). A quantified calcium acculation in hFOB1 was significantly decreased at 1,10, and 100${\mu}g$/ml of nicotine (p<0.05). Significantly decreased calcium deposition was observed at 1, 10, and 100${\mu}$/ml of nicotine. These results indicate that a higher concentration of nicotine show a negative effects on mineralization of hFOB1.

• 대한수의학회지
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• 제54권4호
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• pp.245-252
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• 2014

This study was investigated the change of concentration and toxicity of thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION) on tissues of Sprague-Dawley rats. TCL-SPION at the dose of 15 mg/kg body weight was intravenously injected into the tail vein of the male Sprague-Dawley rats. The fate of TCL-SPION in serum, urine and tissues was observed during 28 days. Serum iron level was maximal at 0.25 h post-injection and gradually declined thereafter. In addition, the sinusoids of liver and the red pulp area of spleen were mainly accumulated iron from 0.5 h to 28-day post-injection. In kidney, iron deposition was detected in the tubular area until 0.5 h after injection. Malondialdehyde concentration in the liver slightly increased with time and was not different with that at zero time. In the liver and spleen, TNF-${\alpha}$ and IL-6 levels of TS treated with TCL-SPION were not different with those of the control during the experimental period. From the results, TCL-SPION could stay fairly long-time in certain tissues after intravenous injection without toxicity. The results indicated that TCL-SPION might be useful and safe as a contrast for the diagnosis of cancer or a carrier of therapeutic reagents to treat diseases.

• 한국재료학회지
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• 제20권4호
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• pp.194-198
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• 2010

Cubic boron nitride (c-BN) is a promising material for use in many potential applications because of its outstanding physical properties such as high thermal stability, high abrasive wear resistance, and super hardness. Even though 316L austenitic stainless steel (STS) has poor wear resistance causing it to be toxic in the body due to wear and material chips, 316L STS has been used for implant biomaterials in orthopedics due to its good corrosion resistance and mechanical properties. Therefore, in the present study, c-BN films with a $B_4C$ layer were applied to a 316L STS specimen in order to improve its wear resistance. The deposition of the c-BN films was performed using an r.f. (13.56 MHz) magnetron sputtering system with a $B_4C$ target. The coating layers were characterized using XPS and SEM, and the mechanical properties were investigated using a nanoindenter. The friction coefficient of the c-BN coated 316L STS steel was obtained using a pin-on-disk according to the ASTM G163-99. The thickness of the obtained c-BN and $B_4C$ were about 220 nm and 630 nm, respectively. The high resolution XPS spectra analysis of B1s and N1s revealed that the c-BN film was mainly composed of $sp^3$ BN bonds. The hardness and elastic modulus of the c-BN measured by the nanoindenter were 46.8 GPa and 345.7 GPa, respectively. The friction coefficient of the c-BN coated 316L STS was decreased from 3.5 to 1.6. The wear property of the c-BN coated 316L STS was enhanced by a factor of two.

• 한국수산과학회지
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• 제27권3호
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• pp.272-281
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• 1994

양식 농어에 대한 사료 carotenoids의 대사와 체색개선에 미치는 영향을 검토하기 위하여 ${\beta}$-carotene, lutein ester, astaxanthin, astaxanthin monoester 및 astaxanthin diester의 첨가사료로서 8주간 사육하여 표피의 carotenoid성분을 분석, 비교 검토한 결과는 다음과 같다. 농어 표피의 carotenoid색소는 tunaxanthin획분과 lutein이 주성분을 이루고 있으며, 그 외 ${\beta}$-carotene, a-cryptoxanthin, zeaxanthin 및 ${\beta}$-carotene type triol이 소량으로 존재하였다. 한편, 천연산은 양식산에 비하여 tunaxanthin과 lutein의 함유비가 높은 반면 ${\beta}$-carotene의 함유비가 낮은 경향을 보여 서로 차이를 보였다. Carotenoid의 축적율은 astaxanthin monoester 첨가구에서 가장 높게 나타나서 체색선명화의 효과가 컸었으며, 그 다음으로 astaxanthin, astaxanthin diester첨가구의 순으로 나타났다. 사육시험후 각 시험구의 carotenoid함량과 조성으로 보아, 농어의 carotenoid대사경로는 astaxanthin이 ${\beta}$-carotene type triol, zeaxanthin, lutein을 거쳐 tunaxanthin으로 되는 환원적대사과정을 가지는 것으로 추정할 수 있었다.

• Journal of Nutrition and Health
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• 제29권10호
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• pp.1059-1071
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• 1996

This study was performed to investigate the effect of dietary protein level on renal senescence. Male rats of 337.8$\pm$5.7g body weight were underlateral nephrectomy or shamoperation. The rats were divided into high protein(40% casein), normal protein(15% casein) and low protein(8% casein)diets and fed experimental diets ad libitum for 24 weeks. The results are summarized as follows. There was a hypertophy of the remnant kidney of uninephrectomized rats of 40% or 15% protein group, coming up to the comparable weights of both kidneys of sham-operated rats. However, the hypertrophic effect was not seen in uninephrectomized rats of 8% protein group. Serum albumin was lower in uninephrectomized rats. With increasing dietary protein level blood urea nitrogen was increased, whereas, urinary urea nitrogen excretion was decreased. Urinary solute excretion was higher in uninephrectomized group than in sham-operated group. However, effect of dietary protein level on urinary solute excretion varied dpending on th solutes tested. GFR and urinary protein excretion, throughout experiment, increased with feeding period and with dietary protein level. Proteinuria was most severe in uninephrectomized rats fed 40% casein diet. Maximum urine concentration ability measured after dehydration was not different among the experimental groups. Light microscopic examination showed focal segmental glomerulosclerosis and mild increas of glomerular mesangial matrix in uninephrectomized rats fed 40% and 15% protein diet, however, which was not observed in uninephrectomized rats fed 8% protein diet and in sham-operated rats fed 40% diet. Immunofluorescence studies revealed segmental deposits of albumin in the mesangium and capillary loops in high protein and uninephrectomized groups. Minimal granular deposition of IgG was noted in the mesangium of all experimental groups. In conclusion, high protein intake accelerated deterioration of renal function and it was correlated with morphological change. Low protein intake was effective in preventing these changes.

• 대한의생명과학회지
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• 제12권1호
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• pp.1-7
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• 2006

Mineral-induced alkaline-reduced water (MRW) is generated by the chemical reaction of water with alkaline earth metals and characterized by high pH and low oxidation-reduction potential. As ROS are believed to have a role in the pathogenesis of obesity, we attempted to determine the effect of MRW on obesity in Sprague-Dawley (SD) rats fed on a high-fat diet. The body weight of the MRW group was significantly lower than that of the control group in most periods of the examination (P<0.05). Serum level of triglycerides (p<0.05) and fat deposition in the livers of the MRW group were found to have been significantly reduced. This suggests that MRW down-regulates lipid metabolism, thereby suppressing obesity. Possible mechanisms of MRW related to reactive oxygen species were also discussed. Our results suggest that MRW is effective in the alleviation of obesity in SD rats fed on high-fat diet.

• Journal of Animal Science and Technology
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• 제54권6호
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• pp.449-454
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• 2012

The present study was performed to investigate the effects of the plane of nutrition on growth performance and meat quality traits, especially marbling and PSE (pale, soft, and exudative), in finishing pigs. One hundred and four barrows and 102 gilts born to Yorkshire ${\times}$ Landrace dams and Duroc sires were randomly allocated to 16 pens at approximately 80-kg body weight, with 13 animals housed per pen except for two pens. Each eight pens received a diet containing either 3.4 Mcal ME/kg and 0.98% total lysine (high plane) or 3.1 Mcal ME/kg and 0.81% total lysine (medium plane). All animals were slaughtered at approximately 112 kg BW on an average, after which the Longissimus muscle (LM) was analyzed physicochemically. The ADG, ADFI, gain:feed as well as marbling score did not differ between the two dietary groups, whereas backfat thickness was greater in the high-plane group than in the medium-plane group (24.1 vs. 22.5 mm P<0.05). No LM exhibited PSE, i.e. $L^*$ (lightness) > 50, pH < 6.0 and drip loss > 5.0%, nor were these PSE-related variables influenced by the dietary treatment. Contents of crude protein and fat in LM did not differ between the two dietary groups. In conclusion, the present results suggest that growth performance and the occurrence of the PSE or 'watery' carcass are not influenced significantly by increasing the plane of nutrition in finishing pigs when the finisher is adequate nutritionally for supporting maximal lean growth. However, increasing the plane of nutrition is likely to result in an increase in fat deposition.