• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.31-37
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• 2013

Lowering surface reflectance of Si wafers by texturization is one of the most important processes for improving the efficiency of Si solar cells. This paper presents the results on the effect of texturing using acidic solution mixtures containing the catalytic agents to moderate etching rates on the surface morphology of mc-Si wafer as well as on the performance parameters of solar cell. It was found that the treatment of contaminated crystalline silicon wafer with $HNO_3-H_2O_2-H_2O$ solution before the texturing helps the removal of organic contaminants due to its oxidizing properties and thereby allows the formation of nucleation centers for texturing. This treatment combined with the use of a catalytic agent such as phosphoric acid improved the effects of the texturing effects. This reduced the reflectance of the surface, thereby increased the short circuit current and the conversion efficiency of the solar cell. Employing this technique, we were able to fabricate mc-Si solar cell of 16.4% conversion efficiency with anti-reflective (AR) coating of silicon nitride film using plasma-enhanced chemical vapor deposition (PECVD) and Si wafers can be texturized in a short time.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.563-574
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• 2007

Laser induced breakdown spectroscopy (LIBS) is a recently developed analytical technique that is based upon the measurement of emission lines generated by atomic species close to the surface of the sample, thus allowing their chemical detection, identification and quantification. With powerful advantages of LIBS compared to the conventional analytical methodology, this technique can be applied in the detection of heavy metals in the field. LIBS allows the rapid analysis by avoiding laborious chemical steps. LES have already been applied for the determination of element concentration in a wide range of materials in the solid, liquid and gaseous phase with simplicity of the instrument and diversity of the analytical application. These feasibility of rapid multi elemental analysis are appealing proprieties for the in-situ analytical technique in geochemical investigation, exploration and environmental analysis. There remain still some limitations to be solved for LIBS to be applied in soil environment as an in-situ analytical technology. We would like to provide the basic principle related to the plasma formation and laser-induced breakdown of sample materials. In addition, the matrix effect, laser properties and the various factors affecting on the analytical signal of LIBS was dealt with to enhance understanding of LIBS through literature review. Ultimately, it was investigated the feasibility of LIBS application in soil environment monitoring by considering the basic idea to enhance the data quality of LIBS including the calibration method for the various effects on the analytical signal of LIBS.

• Applied Microscopy
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• v.31 no.1
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• pp.37-47
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• 2001

In order to investigate a pathogenesis of liver damage induced by skin burn, thermal injury was induced by scald burn on entirely dorsal surface in rats (total burn surface area $20\sim25\%$) except for inhalated injury. At 5 and 24 h after scald burn, biochemical assay and morphological changes in serum and liver tissue were examined. Skin burn increased liver weight (% of body weight, p<0.05) and the activity of serum aniline amino-transferase (ALT, p<0.05), in addition, the activity of xanthine oxidase (XO), an enzyme of oxygen free radical generating system, was elevated (p<0.01) in serum, but not in skin and in liver. Postburn treatment of allopurinol intraperitoneally decreased liver weight, serum ALT activity and serum XO activity. Scald burn induced ultrastructurally swelling of endoplasmic reticulum, ribosome detachment, accumulation of lipid, dilatation of bile canaliculi and intercellular space, neutrophil infiltration, activation of Kupffer's cells and degeneration of hepatocytic microvilli. Futhermore , thermal injury decreased not only the protein concentration in plasma but also the number of intravascular leukocytes, that indicates induction of edema formation with protein exudation and inflammation by neutrophil infiltration into the internal organs. However allopurinol injection after burn inhibited post burn ultrastructural changes. These data suggest that acute dermal scald burn injury leads to liver damage, that is related to elevation of xanthine oxidase activity in serum. Xanthine oxidase may be a key role in the pathogenesis of liver damage induced by skin burn.

• Journal of Periodontal and Implant Science
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• v.36 no.4
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• pp.797-808
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• 2006

Objective : The purpose of this study was to evaluate the physicochemical properties and cytocompatibility of microporous, spherical biphasic calcium phosphate(BCP) ceramics with a 60/40 $hydroxyapatite/{\beta}$ -tricalcium phosphate weight ratio for application as a bone graft substitute. Materials and Methods : Microporous, spherical BCP granules(MGSB) were prepared and their basic characteristics were compared with commercially available BCP(MBCP; Biomatlante, France) and deproteinized bovine bone mineral(Bio-Oss; GBistlich-Pharma, Switzerland, BBP; Oscotec. Korea), Their physicochemical properties were evaluated by scanning electron microscopy, X-ray diffractometry, Fourier-transform infrared spectroscopy, inductively coupled plasma atomic emission spectrometer, and Brunauer-Emmett-Teller method. Cell viability and proliferation of MC3T3-El cells on different graft materials were evaluated. Results : MGSB granules showed a chemical composition and crystallinity similar with those in MBCP, they showed surface structure characteristic of three dimensionally, well-interconnected micropores. The results of MTT assay showed increases in cell viablity with increasing incubation times. At 4d of incubation, MGSB, MBCP and BBP showed similar values in optical density, but Bio-Oss exhibited significantly lower optical density compared to other bone substitutes(p <0,05). MGSB showed significantly greater cell number compared to other bone substitutes at 3, 5, and 7d of incubation(p <0,05), which were similar with those in polystyrene culture plates. Conclusion: These results indicated the suitable physicochemical properties of MGSB granules for application as an effective bone graft substitute. which provided compatible environment for osteoblast cell growth. However, further detailed studies are needed to confirm its biological effects on bone formation in vivo.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.1035-1041
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• 1996

Klinefelter's syndrome is characterized by small testes, azoospermia, gynecomastia, and elevated levels of plasma gonadotropins in men with two or more X chromosomes. Previous investigators reponed that patients with Klinefelter's syndrome are predisposed to the development of a non-seminomatous germ cell tumor in the mediastinum. It is suggested that this linkage may be due to the hormonal imbalance in Klinefelter's syndrome and consequently, the formation of dysgenetic germ cell and/or abnomal migration of germ cell We report here a case of Klinefelter's syndrome in a 24-years-old man who was presented with anterior mediastinal mass. The clinical and laborarotory fmdings were compatible with Klinefelter's syndrome and he was found to have 47 XXY karyotype. Pathological findings for mediastinal mass revealed mixed germ cell tumor composed of mature cystic teraloma and endodermal sinus rumor. He was treated with cis platin containing chemotherapy and followed up in partial remission.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.5
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• pp.417-433
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• 2006

Purpose : Platelet rich plasma (PRP) is an autologous material with many growth factors, such as BMPs, PDGF, $TGF-{\beta}_1$, $TGF-{\beta}_2$, VEGF, and IGF, facilitating bone healing process. The prominent osteoconductive activity and the biodegradable nature of beta-tricalciumphosphate (${\beta}-TCP$) for bone grafts in animal experiments have been reported. The purpose of this study was to evaluate the effect of PRP on the osteogenesis of ${\beta}-TCP$. Materials & Methods : Two artificial calvarial bone defects were made in 32 rabbits which were divided into 2 groups. In one group of 16 rabbits, autogenous bone / ${\beta}-TCP$ was grafted on each side of cranial bone defect. In the other group of 16 rabbits, mixture of ${\beta}-TCP$ and PRP / PRP alone was grafted on each side of the cranial bone defect. The animals were sacrificed at 2, 4, 8, and 12 weeks after surgery. The specimens were harvested and examined histologically and immunohistochemically by the expression of BMP2/4/7, PDGF, VEGF and $TGF-{\beta}_1$. Results : The mean volume of new bone formation was significantly higher at 4, 8, 12 weeks in autogenous graft than that in ${\beta}-TCP$. The BMP2/4 expression was significantly higher at 4 weeks in autogenous bone graft and at 4 weeks in mixture of ${\beta}-TCP$ and PRP and at 12 weeks in ${\beta}-TCP$. The expression of BMP7, PDGF, VEGF and $TGF-{\beta}_1$ showed no significant difference in autogenous, ${\beta}-TCP$, mixture of ${\beta}-TCP$ and PRP, and PRP alone during grafted bone regeneration. Conclusion : The results showed that PRP had no additional value in promoting healing process of ${\beta}-TCP$ grafts.

• Polymer(Korea)
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• v.36 no.4
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• pp.542-548
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• 2012

Morphological characteristics and formation of symmetric polystyrene-block-poly(1,4-butadiene) copolymer (PS-b-PBD) in thin films upon solvent-annealing were investigated by using atomic force microscopy (AFM). The thin films solvent-annealed in cyclohexane revealed the perforated lamellae of poly(1,4-butadiene) in the matrix of polystyrene while those solvent-annealed in n-hexane exhibited highly disordered patterns. Interestingly, when the thin films of PS-b-PBD were solvent-annealed with binary mixtures of cyclohexane and n-hexane, the morphological transition from the perforated lameallae to the perpendicularly-oriented lamellae of poly(1,4-butadiene) could be induced by changing the mixing ratio of both solvents. We also demonstrated that after microdomians of poly(1,4-butadiene) were successfully degraded by UV-$O_3$, linear poly(dimethyl siloxane) chains were back-filled into the etched regions of the thin film and then converted to silica nano-objects by oxygen plasma treatments.

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.100-105
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• 2012

Analysis of the various constituents and determination of biological activities in the different parts (root, stem, and leaf) of Allium victorialis var. platyphyllum were carried out. Potassium and calcium were detected in higher contents (mg/100 g fresh wt.) than other minerals. The total phenolic content (mg tannic acid eq./100 g dry wt.) decreased in the order of leaves ($792.7{\pm}16.6$) > stems ($160.3{\pm}6.8$) > roots ($101.5{\pm}2.7$), and the total flavonoid content (mg quercetin eq./100 g dry wt.) was as follows: leaves ($497.9{\pm}11.1$), roots ($35.7{\pm}0.4$), stems ($18.5{\pm}1.4$). DPPH radical-scavenging activity and inhibition activity against the formation of cholesteryl ester hydroperoxide in rat blood plasma was higher in the leaves than in roots and stems. Extracts of A. victorialis separated by parts displayed antimicrobial activity against Clostridium perfringens, Staphylococcus aureus, Listeria monocytogenes, Vibrio vulnificus, Vibrio parahaemolyticus, of which the strongest activity was against C. perfringens.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.46-53
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• 2003

The current study investigated the effect of Korean safflower (Carthamus tinctorius L.) seed powder and its water and ethanol extracts on bone metabolism during recovery from rib-fracture induced by surgical operation in rats. 10-week-old male Sprague-Dawley rats weighing about 320 g were divided into 9 groups after arrival: 10d control (AIN 76 semi-purified diet), 10d safflower seed powder (10d SS-powder), 10d safflower seed ethanol extract (10d SS-EtOH), 10d safflower seed water extract (10d SS-$H_2O$), 20d control (AIN-76 semi-purified diet), 20d safflower heed powder (20d SS-powder), 20d safflower seed ethanol extract (20d SS-EtOH), 20d safflower seed water extract (20d SS-$H_2O$), and 20d sham-operation (20d sham), The dietary level for all the supplements was 5% based on the raw material weight. The rats were fed the experimental diets for 10 days before the rib fracture operation and for a further 10 or 20 days after the operation. A number 9 rib was fractured surgically and a sham-operation also performed. The rats were then sacrificed on the l0th or 20th day after the operation. The body weight initially decreased after the operation in all the rib-fractured groups, then gradually recovered. The concentrations of plasma osteocalcin were higher in the control group than in all the safflower-supplemented groups 10 and 20 days after the rib-fracture (p < 0.05). The bone-specific ALP (alkaline phosphatase) activity was significantly higher in the SS-EtOH group than in the other groups 20 days after the rib-fracture (p < 0.05). The level of urinary DPD (deoxypridinoline) was significantly higher in the SS-EtOH and SS-$H_2O$ groups than in the other groups 10 days after the rib-fracture. When comparing the PTH (parathyroid hormone) and calcitonin levels, the SS-$H_2O$ group exhibited the highest PTH level among the groups 10 and 20 days after the rib-fracture. Thus, it was concluded that the bone turnover during the fracture-healing period was more rapid in the rats supplemented with safflower seed powder or its fractions than in the control rats. Furthermore, the SS-$H_2O$ fraction was identified as the most effective in stimulating bone remodeling, as bone resorption and bone formation were both significantly increased during fracture healing when compared to the control group.

• Journal of Chitin and Chitosan
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• v.23 no.4
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• pp.267-276
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• 2018

This study was performed to investigate the ameliorating effect of a hangover beverage mixture (SBJ) that contains Dendropanax morbifera Lev. and several medicinal plant extracts, on hepatoprotection and alcohol-metabolizing enzymes in alcohol-induced hangover in both in vitro and in vivo models. In human hepatoma cell line, HepG2, 300 mM of ethanol-induced hepatotoxicity was significantly improved by pretreatment of SBJ by dose-dependent manner. In the in vivo study, administration of alcohol to rats raised to the concentration of blood alcohol and lactate dehydrogenase (LDH). Blood alcohol and LDH levels in SBJ-treated rats significantly decreased at 0.5 h and 8 h after acute ethanol administration (40%, 4.6 g/kg body weight) as compared to alcohol-treated rats. Hepatic alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity were significantly higher in SBJ-treated rats than in alcohol-treated rats. SBJ supplementation reduced formation of malondialdehyde (MDA), and inhibited reductions of hepatic superoxide dismutase (SOD), hepatic glutathione (GSH), glutathione-S-transferase (GST), glutathione reductase (GR) and glutathione peroxidase (GPx) levels, compared with rats administered alcohol. Plasma catalase (CAT), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels showed unaltered resulted in all experimental groups compared with the control group. These results suggest that SBJ exhibit hepatoprotective properties by enhancing ADH, ALDH activity and stimulating the antioxidant defense system in alcohol-induced hangover.