• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.3
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• pp.249-257
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• 2007

State of problem : The use of zirconium oxide all-ceramic material provides several advantages, including a high flexural strength(>1000MPa) and desirable optical properties, such as shading adaptation to the basic shades and a reduction in the layer thickness. Along with the strength of the materials, the cementation technique is also important to the clinical success of a restoration. Nevertheless, little information is available on the effect of different surface treatments on the bonding of zirconium high-crystalline ceramics and resin luting agents. Purpose : The aim of this study was to test the effects of surface treatments of zirconium on shear bond strengths between bovine teeth and a zirconia ceramic and evaluate differences among cements Material and methods : 54 sound bovine teeth extracted within a 1 months, were used. They were frozen in distilled water. These were rinsed by tap water to confirm that no granulation tissues have left. These were kept refrigerated at $4^{\circ}C$ until tested. Each tooth was placed horizontally at a plastic cylinder (diameter 20mm), and embedded in epoxy resin. Teeth were sectioned with diamond burs to expose dentin and grinded with #600 silicon carbide paper. To make sure there was no enamel left, each was observed under an optical microscope. 54 prefabricated zirconium oxide ceramic copings(Lava, 3M ESPE, USA) were assigned into 3 groups ; control, airborne-abraded with $110{\mu}m$ $Al_2O_3$ and scratched with diamond burs at 4 directions. They were cemented with a seating force of 10 ㎏ per tooth, using resin luting cement(Panavia $F^{(R)}$), resin cement(Superbond $C&B^{(R)}$), and resin modified GI cement(Rely X $Luting^{(R)}$). Those were thermocycled at $5^{\circ}C$ and $55^{\circ}C$ for 5000 cycles with a 30 second dwell time, and then shear bond strength was determined in a universal test machine(Model 4200, Instron Co., Canton, USA). The crosshead speed was 1 mm/min. The result was analyzed with one-way analysis of variance(ANOVA) and the Tukey test at a significance level of P<0.05. Results : Superbond $C&B^{(R)}$ at scratching with diamond burs showed the highest shear bond strength than others (p<.05). For Panavia $F^{(R)}$, groups of scratching and sandblasting showed significantly higher shear bond strength than control group(p<.05). For Rely X $Luting^{(R)}$, only between scratching & control group, significantly different shear bond strength was observed(p<.05). Conclusion : Within the limitation of this study, Superbond $C&B^{(R)}$ showed clinically acceptable shear bond between bovine teeth & zirconia ceramics regardless of surface treatments. For the surface treatment, scratching increased shear bond strength. Increase of shear bond strength by sandblasting with $110{\mu}m$ $Al_2O_3$ was not statistically different.

• Journal of the Korean Society of Radiology
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• v.5 no.2
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• pp.93-96
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• 2011

Currently, the development of direct conversion radiation detector using photoconductor materials is progressing in widely. Among of theses photoconductor materials, mercuric iodide compound than amorphous selenium has excellent absorption and sensitivity of high energy radiation. Also, the detection efficiency of signal generated in photoconductor film varies by electric filed and geometric distribution according to top-bottom electrode size. Therefore, in this work, the x-ray detection characteristics are investigated about the size of top electrode in $HgI_2$ photoconductor film. For sample fabrication, to solve the problem that is difficult to make a large area film, we used the spatial paste screen-print method. And the sample thickness is $150{\mu}m$ and an film area size is $3cm{\times}3cm$ on ITO-coated glass substrate. ITO(Indium-Tin-Oxide) electrode was used as top electrode using a magnetron sputtering system and each area is $3cm{\times}3cm$, $2cm{\times}2cm$ and $1cm{\times}1cm$. From experimental measurement, the dark current, sensitivity and SNR of the $HgI_2$ film are obtained from I-V test. From the experimental results, it shows that the sensitivity increases in accordance with the area of the electrode but the SNR is decreased because of the high dark current. Therefore, the optimized size of electrode is importance for the development of photoconductor based x-ray imaging detector.

• Radiation Oncology Journal
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• v.15 no.3
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• pp.175-186
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• 1997

Purpose : To evaluate the qualitative immunologic changes by ionizing radiation. we studied the altered capacities of the macrophages and lymphocytes to produce cytokines in conjunction with resistance to Listeria monocytegenes (LM) infection in mice Materials and Methods : BALB/c mice and Listeria monocytogenes were used. The mice were infected intraperitoneally with $10^5LM$ at 1 day after irradiation (300cGy) and sacrificed at 1, 3, 5 days after infection, and then the numbers of viable LM per spleen in the irradiated and control group were counted. Tumor necrosis factor-alpha ($TNF-\alpha$), interferon-gamma ($IFN-\gamma$). interleukin-2 (IL-2), and nitric oxide (NO) were assessed after irradiation. Results : Under gamma-ray irradiation with a dose range of 100-850cGy, the number of total splenocytes decreased markedly in a dose-dependent manner, while peritoneal macrophages did so slightly Cultured peritoneal macrophages produced more $TNF-\alpha$ in the presence of lipopolysaccharide (LPS) during the 24 hours after in vitro irradiation, but their capacity of $TNF-\alpha$ Production showed a decreased tendency at 5 days after in vivo total body irradiation. With 100cGy and 300cGy irradiation, cultured peritoneal macrophages produced more NO in the presence of LPS during the 24 hours after in vitro irradiation than without irradiation. Activated splenocytes from irradiated mice (300cGy) exhibited a decreased capacity to Produce IL-2 and $IFN-\gamma$ with Concavalin-A stimulation at 3 days after irradiation. When BALB/c mice were irradiated to the total body with a dose of 300cGy, they showed enhanced resistance during early innate phase, but a significant inhibition of resistance to LM was found in the late innate and acquired T-cell dependent phases. Conclusion : These results su99es1 that increased early innate and decreased late innate and acquired immunity to LM infection by ionizing radiation (300cGy) may be related to the biphasic altered capacity of the macrophages to produce $TNF-\alpha$ and the decreased capacities of the lymphocytes to produce IL-2 and $IFN-\gamma$ in addition to a marked decrease in the total number of cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1179-1186
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• 2010

The antiradical property of hot water extract from dried radish (DR) or dried radish roasted with pressure (DRRP) was investigated in vitro and in LLC-PK1 cell system. The contents of total free amino acid and reducing sugar in DR were decreased by 72.86% and 3.17%, respectively, after pressurized roasting. In vitro test, $IC_{50}$ for DR and DRRP for DPPH radical scavenging activity were 646.70 and $135.45\;{\mu}g/mL$, 896.10 and $566.98\;{\mu}g/mL$ for superoxide anion radical, and 722.26 and $531.84\;{\mu}g/mL$ for hydroxy radical, respectively. The radical scavenging effects of DRRP was significantly greater than those for DR (p<0.001). These radical scavenging effects of DR and DRRP were confirmed in LLC-$PK_1$ at which oxidative stresses were induced by superoxide, nitric oxide and peroxynitrite generated in the treatment of pyrogallol, SNP, and SIN-1, respectively. Cell viability was increased in the presence of DR or DRRP, dose dependently (p<0.05), and TBARS formation was decreased. The protective effects of DRRP against oxidative damage in LLC-$PK_1$ were greater than those of DR at the same concentration tested (p<0.05). This superior antiradical activity of DRRP might be due to the products produced during the pressurized roasting in addition to the antioxidative compounds originally present in the radish. 5-hydroxyl methyl furfural (5-HMF) known as an intermediate product of the maillard reaction was detected in DRRP (0.57 mg/g), but not from DR. In conclusion, daily consumption of DRRP may prevent oxidative damage by retarding oxidative stress.

• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.124-132
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• 2020

The purpose of this study was to investigate the biological activities such as cytotoxicity and anti-inflammation using Manjakani (Quercus infectoria Olivier) extract. Manjakani was extracted from hot DW and 80% ethanol. Cell viability was assessed using MTT assay on RAW 264.7 cells. Also, anti-inflammatory activities were measured through changes in the levels of nitric oxide (NO), prostaglandin E₂ (PGE₂), leukotrien B4 (LTB₄), pro-inflammatory cytokines (IL-1β, IL-6 and tumor necrosis factor (TNF)-α) and transcription factor on LPS-induced RAW264.7 cells. The results confirmed that significant cytotoxicity does not appear in the concentration range of 1, 5, and 10 ㎍/㎖ of both extracts of this study. The production of NO was slowed by approximately MDE 37.2% and MEE 43.7% at 10 ㎍/㎖ concentration. Also, level of PGE₂ and LTB₄ was decreased MDE 30.9%/MEE 43.7% and MDE 37.1%/MEE 43.7%. In the case of inflammatory cytokine was reduced to MDE 38.8%/MEE 50.8% for IL-1β, MDE 35.0%/MEE 44.2% for IL-6 and MDE 31.9%/MEE 36.6% for TNF-α at 10 ㎍/㎖ concentration. The mRNA expression of NF-κB, iNOS and COX-2 significantly decreased by MDE 44.0%/MEE 16.0%, MDE 44.0%/MEE 55.0% and MDE 45.0%/MEE 40.0%, respectively, following the 10 ㎍/mL sample treatment when compared to the control. Both extracts were effective in anti-inflammatory activity. In addition, both extracts showed efficient changes of production of NO, PGE₂, LTB₄, pro-inflammatory cytokines and transcription factor. But MEE was found to have a higher inhibitory effect than MDE. In other words, Manjakani was showed significant biological activities showing anti-inflammation without cytotoxicity. These results will be provided as fundamental data for further development of the new health food and therapeutics related to the results above.

• 보존과학연구
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• s.17
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• pp.161-182
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• 1996

In natural atmosphere, copper and copper alloy have been used to make buddha statues and ornaments of historic buildings since the abovementioned metals have corrosion resistance in some extent, and the patinaformed on the surface of the metals has provided the people aesthetic satisfaction with its beauty. But in atmosphere polluted by $SO_x$and $NO_x$, the patina layer does not work as a protective film, and it allows damages of the metal. Since 1992, Tokyo National Research Institute of Cultural Properties(TNRICP)has conducted studies on the influence of atmospheric pollution on metal cultural property held under open air. The Great Buddha Image which is located in Kamakura about 50km west from Tokyo, has been selected as one of the objects to study because it is made by copper alloy and it has stood exposed in the air for about a few hundreds years. Furthermore it is also the reason to study on it that there are many cultural properties in the surroundings of it. We have analysed the components and the structure of the corrosion products formed on the surface of the Buddha, have carried out exposure tests using the alloy samples which have simulated the components of the Great Image, and have observed climated and polluted air in order to discuss the relation between corrosion of metals in open air and conditions of the atmosphere. In this paper, the authors have described the components and the structure of the corrosion product formed on the surface of the Great Image by means of X-ray fluorescence spectroscopy and X-ray diffraction. The conclusions are as follows. (1) Sulfate patina composed mainly with brochantite were detected on the all sides of the Image and the amount of the patina is found more on the back of the Image facing to north. (2) Antlerite were detected on the back and a park of the left side facing to west, and formation of it was considered to have close relation with malignant atmosphere. (3) A big amount of chloride patina which mainly composed of atacamite were observed on the front facing to south. (4) Carbonate patina mainly composed of malachite were detected on the area where brochantite was often detected as well. It suggested that malachite had been transformed into brochantite by deteriorated atmosphere. (5) On the all sides of the Image, patina were observed together with copper oxides mainly composed of cuprous oxide. It showed that the surface layer of the Image consists of two layers : inner layer of oxide and outer layer of patina. (6) Corrosion products of lead which was a component of copperalloy were detected on the all sides : the main lead product found on the front was chlorophosphate whereas the one on the back was sulfate.

• Parasites, Hosts and Diseases
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• v.29 no.4
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• pp.381-388
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• 1991

Trichomonas vaginalis is a parasitic nagellate in the urogenital tract of human. Innate cytotonicity of macrophages against T. vaginalis has been recognized, but any report on the cytotoxicity of Iymphokine-activated macrophages to T vaginalis is not yet available. The present study aimed to elucidate the Iymphokine-activated cell mediated cytotoxic effect against T. vaginalis by mouse peritoneal macrophages. Cytotoxicity was measured by counting the release of $^3H-thymidine$ from prelabeled protozoa, and tested in U-bottom microtiter plates. Nitrite concentration in culture supernatants was measured by standard Griess reaction. The results obtained are as follows: 1, The cytotoxicity of macrophages was increased by addition of rIL-2 or $rIFN-{\gamma}$$. 2, Cytotoxicity of macrophages was reduced by addition of rIL-4 to rOM-CSV, rIL-2 or $rIFN-{\gamma}$. 3. Crude Iymphokine mixed with anti-lL-2 decreased the cytotoxity of macrophages. 4. In case of macrophages cultured with $rIFN-{\gamma}$ or rIL-4, the concentration of nitrite was related with cytotokity of macrophages against T. vaginalis, but the cytotoxicity of macrophages cultured with rIL-2 and $rIFN-{\gamma}$ was decreased in spite of its high production of llitrite. From the results obtained, it is assumed that rIL-2 and $rIFN-{\gamma}$ enhance the cytotoxicity of macrophages while rIL-4 inhibits the cytotoxicity against T. vaginalis, and that the production of nitrite does not relate with the cytotoxicity of macrophages, but nitric oxide may play a role as an inhibitory factor on the proliferation of T. vaginalis.

• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.189-197
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• 2022

Asthma is a chronic inflammatory disease characterized by recurring symptoms, airflow obstruction, and bronchial hyper-responsiveness. The onset of asthma for most patients begins early in life, and current asthma treatment with anti-inflammatory agents can have adverse effects, eventually leading to impaired quality of life. In the pathogenesis of asthma, macrophages and basophils play a vital role during progression. Macrophages not only induce inflammation by secreting inflammatory cytokines but also promote DNA damage and mucus production through nitric oxide (NO) production. Basophils enhance eosinophil recruitment and aggravate asthma through the FcεRIα receptor with high affinity for histamine and IgE. Therefore, in this study, we investigated whether the activation of macrophages and basophils is suppressed by the individual extracts of 28 natural products. RAW 264.7 cells (mouse macrophages) were treated with the natural products in LPS, and 4 natural product extracts resulted in decreased NO production. In β-hexosaminidase assay using RBL-2H3 cells (rat basophils), 19 natural product extracts decreased β-hexosaminidase production. In NO production and β-hexosaminidase assay using macrophages and basophils, 3 natural product extracts (Plantago asiatica, Centella asiatica, and Perilla frutescens var. japonica) significantly inhibited NO production and β-hexosaminidase release. Overall, we examined the inhibitory effects of 28 natural product extracts on macrophage and basophil activity, and the findings demonstrated the potential of natural product extracts for treating asthma and macrophage- and basophil-related diseases.

• Journal of Powder Materials
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• v.20 no.2
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• pp.142-147
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• 2013

$YBa_2Cu_3O_{7-y}$ (Y123) powders for the fabrication of bulk superconductors were synthesized by the powder reaction method using $Y_2O_3$ (99.9% purity), $BaCO_3$ (99.75%) and CuO (99.9%) powders. The raw powders were weighed to the cation ratio of Y:Ba:Cu=1:2:3, mixed and calcined at $880^{\circ}C-930^{\circ}C$ in air with intermediate repeated crushing steps. It was found that the formation of Y123 powder was more sensitive to reaction temperature than reaction time. The calcined Y123 powder and a mixture of (Y123 + 0.25 mole $Y_2O_3$ + 1 wt.% $CeO_2$, $Y_{1.5}Ba_2Cu_3O_x$ (Y1.5)) were used as raw powders for the fabrication of poly-grain or single grain superconductors. The superconducting transition temperature ($T_{c,onset}$) of the sintered Y123 sample was 91 K and the transition width was as large as 11 K, whereas the $T_{c,onset}$ of the melt-grown Y1.5 sample was 90.5 K and the transition width was 3.5 K. The critical current density ($J_c$) at 77 K and 0 T of the sintered Y123 was 700 $A/cm^2$, whereas the $J_c$ of the top-seeded melt growth (TSMG) processed Y1.5 sample was $3.2{\times}10^4\;A/cm^2$. The magnetic flux density (H) at 77 K of the TSMG-processed Y123 and Y1.5 sample showed the 0.53 kG and 2.45 kG, respectively, which are 15% and 71% of the applied magnetic field of 3.5 kG. The high H value of the TSMG-processed Y1.5 sample is attributed to the formation of the larger superconducting grain with fine Y211 dispersion.

• Journal of Life Science
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• v.23 no.6
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• pp.804-811
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• 2013

Melanopsin is an opsin-like photopigment found in the small proportion of photosensitive ganglion cells of the retina. It is involved in the regulation of the synchronization of the circadian cycle as well as in the control of pupillary light reflex. The purpose of the present study is to investigate whether melanopsin is also expressed in the other areas of the central visual system outside the retina. We have studied the distribution and morphology of neurons containing melanopsin in the mouse visual cortex with antibody immunocytochemistry. Melanopsin immunoreactivity was mostly present in neuronal soma, but not in nuclei. We found that melanopsin was present in a large subset of neurons within the adult mouse visual cortex with the highest density in layer II/III. In layer I of the visual cortex, melanopsin-immunoreactive (IR) neurons were rarely encountered. In the mouse visual cortex, the majority of the melanopsin-IR neurons consisted of round/oval cells, but was varied in morphology. Vertical fusiform and pyramidal cells were also rarely labeled with the anti-melanopsin antibody. The labeled cells did not show any distinctive distributional pattern. Some melanopsin-IR neurons in mouse visual cortex co-localized with nitricoxide synthase, calbindin and parvalbumin. Our data indicate that melanopsin is located in specific neurons and surprisingly widespread in visual cortex. This finding raises the need of the functional study of melanopsin in central visual areas outside the retina.