• Tuberculosis and Respiratory Diseases
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• v.50 no.4
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• pp.450-461
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• 2001

Background : The underlying pathogenesis of radiation-induced lung fibrosis (RTLF) has not been very well defined. However, the role of TGF-$\beta$ in the generation of RTLF has been a major focus because there is an increase in the expression of both the TGF-${\beta}m$-RNA and its protein preceding RTLF lesions. The down stream signal after a TGF-$\beta$ stimulated lung fibrosis includes the activation of many mediators such as Smad and c-Jun N-terminal kinase (JNK) through TAK1. It is we hypothesized that JNK activation may play a pivotal role in RTLF pathogenesis through increased transcription of the fibrogenic cytokines. The present study evaluates JNK activity in alveolar macrophages after irradiation and the relationship between JNK activity and the amount of collagen in the lung tissues. Methods : C57BL/6 mice(20-25 gr, males) received chlorotetracycline(2g/L) in their drinking water 1 week prior to irradiation and continuously there after. The mice were irradiated once with 1400 cGy of $60CO{\gamma}$-ray over the whole chest. The cellular composition of the whole lung bronchoalveoalr lavage fluids(BALF), elastin expression in the lung tissues, the level of hydroxyproline in lung tissues, and an in vitro JNK assay was measured before irradiation and one, four, and eight weeks after irradiation (RT). Results : The volumes of BALF retrieved from instilled 4 mL of saline with 2% heparin were 3.7-3.8 mL for each group. The cell numbers were similar before($4.1{\times}10^4{\pm}0.5{\times}10^4/mL$) and 1 week($3.1{\times}10^4{\pm}0.5{\times}10^4/mL$) after RT. At four and eight weeks after RT, the cell number reached to $14.0{\times}10^4{\pm}1.5{\times}10^4mL$ and $10.0{\times}10^4{\pm}1.3{\times}10^4/mL$, respectively. There we no changes in the lymphocytes and neutrophils population observed in the BALF after RT. The H-E stain of the lung tissues did not show any structural and fibrotic change in the lung tissues at 4 and 8 weeks after RT. In addition, the amount of elastin and collagen were not different on Verhoeff staining of the lung tissues before RT to eight weeks after RT. The hydroxyproine content was measured with the left lung dissected from the left main bronchus. The lung were homogenized and hydrolyzed with 6 N Hel for 12 hours at $110^{\circ}C$ then measured as previously described. The content of hydroxyproline, standardized with a lung protein concentration, reached a peak 4 weeks after RT, and thereafter showed a plateau. AnIn vitro JNK assay using c-$Jun_{1-79}$-GST sepharose beads were performed with the alveolar macrophages obtained from the BAL. JNK activity was not detected prior to RT, However, the JNK activity increased from one week after RT and reached a peak four weeks after RT. Conclusion : JNK may be involved in the pathogenesis because the JNK activity showed similar pattern observed with the hydroxyproine content. However, it is necessary to clarify that the JNK increases the transcription of fibrogenic cyiokines through the transcription factor.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.5
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• pp.187-192
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• 2011

Tilt angle of r-plane wafer is a one of the important factors related with the quality of the GaN epi, so the fine control of the tilt angle is important for the growing of high quality non-polar a-GaN epi. We prepared the R-plane sapphire wafers with slight tilt angles for nonpolar a-plane GaN. The target tilt angles of ${\alpha}$ and ${\beta}$ were 0, -0.1, -0.15, -0.2, -0.4, $-0.6^{\circ}$ and -0.1, 0, $0.1^{\circ}$, respectively. The tilt angles of sliced R-plane sapphire wafers were measured by x-ray and the statistical evaluation of reliability of tilt angles of wafers were performed. The tolerance of the tilt angle was ${\pm}0.03^{\circ}$. R-plane sapphire wafers have relatively large distributions of BOW and TTV data than c-plane sapphire wafers due to the large anisotropy of R-plane. As the tilt angle ${\alpha}$ was increased from -0.1 to $-0.6^{\circ}$, the step widths and heights were decreased from 156 nm to 26 nm and 0.4 nm to 0.2 nm, respectively. The growth and qualities of GaN epi seems to be largely affected by the change of step structure of R-plane sapphire wafers with tilt angle.

• Bulletin of the Korean Chemical Society
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• v.21 no.10
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• pp.951-952
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• 2000

Acylation of an intermediate tetrahydroxoplatinum(IV) complex, $[Pt(OH)_4(dach)]$ (dach = $trans-(\pm)-12-di-aminocyclohexane)$, with one or two kinds of carboxylic anhydrides in stepwise manner afforded various car-boxylatoplatinum(IV) complexes, $[Pt(O_2CR)\chi(OR’)4-\chi(dach)]$ (R = $(CH_2)_3CH_3$ or $C(CH_3)_3$, R’ = H or $OCCH_3$, and $\chi$ = 1-4) with a wide range of lipophilicity. The title complexes were subjected to bioassay using the murine leukemia L1210 cell line, and in particular, their in vivo oral antitumor activity was attempted to correlate with their lipophilicity and water solubility. The most orally active complex exhibited intermediate lipophilicity and water solubility, but it has been found that an exact relationship between the lipophilicity and oral anticancer activity could not be established, since the lipophilicity of the complexes is not the sole parameter to determine the oral activity. One of the important intermediate complexes partially substituted was subjected to X-ray anal-ysis for positit of the substituted group: $[Pt(OPiv)_3(OH)(dach)]$ crystallizes in the tetragonal sys-tem, space group $P42_1c$ with a = 21.161(3) $\AA$, b = 21.161(6) $\AA$, c = 12.816(3) $\AA$, $\alpha=\beta=$ r $=90^{\circ}$, V = 5739(2) $\AA^3$ and Z = 8.

• Atmosphere
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• v.18 no.2
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• pp.97-109
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• 2008

The aerosol characteristics in terms of 4 different cases (Asian dust, fog, clear sky and cloud) which had happened at Anmyeon Island in April 2006 were studied using various measurements such as the Micro Pulse Lidar (MPL), sunphotometer, $\beta$-ray $PM_{10}$ Analyzer, anemoscope and anemometer. In addition, synoptic charts, back trajectory analyses and satellite images were also used to help characterize the aerosol events. The aerosol optical properties were featured by the Aerosol Optical Depth (AOD) and ${\AA}ngstr\ddot{o}m$ exponent which were estimated by the sunphotometer. When Anmyeon Island was dominated by the Asian dust, the AOD was sharply increased as seven times as a yearly average of it (0.35). As compared with a yearly average of the ${\AA}ngstr\ddot{o}m$ exponent of 0.97, the ${\AA}ngstr\ddot{o}m$ exponent of a dust day was significantly low (0.099). In addition, $PM_{10}$ mass concentration showed an extremely high record. The maximum concentration reached $1790.5{\mu}gm^{-3}$ on 8 April 2006. The maximum mass concentration was shown with delay when the wind speed of $0ms^{-1}$ was observed. It was also found that a satellite image of the MODIS-RGB had a good agreement with the results of those measurements. It was shown that the MPL was able to describe effectively the vertical distribution of aerosol for all the cases. In particular, the MPL evidently captured the aerosol layer before the cloud observation. The aerosol layer was similarly described by the AOD. On a clear sky day, the AOD had not only a very low value (0.054) but also a feature of homogeneity.

• Corrosion Science and Technology
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• v.12 no.1
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• pp.50-55
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• 2013

The purpose of this study was to investigate corrosion characteristics of Ti-xTa alloys with Ta contents. Ti-xTa alloys used as samples (x=30, 40%) were arc-melted under argon atmosphere of 99.9% purity. Ti-xTa alloys were homogenized for 12hr at $1000^{\circ}C$ and then water quenched. The surface characteristics of Ti-xTa alloys were investigated using optical microscopy (OM) and X-ray diffractometer (XRD). The anodic corrosion behaviors of the specimens were examined through potentiodynamic, potentiostatic and galvanostatic test in 0.9 % NaCl solution at $36.5{\pm}1^{\circ}C$. After corrosion test, the surface characteristics of Ti-xTa alloys were investigated using OM. The microstructure of Ti-Ta alloy showed the beta structure with Ta content. The corrosion resistance of Ti alloy was improved by increasing Ta content and the corrosion morphology of Ti-Ta alloy showed that the site attacked by chloride ion decreased from the active to passive region with Ta content. Potential of Ti-40Ta alloy increased as time increased, whereas, current density of Ti-40Ta alloy decreased as time increased compared to Ti-30 alloy.

• Bulletin of the Korean Chemical Society
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• v.29 no.6
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• pp.1157-1161
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• 2008

2,6-Dinitrophenol (2,6-DNP) complexes with lanthanide series including yttrium (except Pm, Tm, and Lu) have been synthesized and their crystal structures have been analyzed by X-ray diffraction methods. Singlecrystal X-ray structure determinations have been performed at 296 K on the Ce$\rightarrow$Yb species and shown them to be isomorphous, triclinic, P1, a = 8.6558(2)$\rightarrow$8.5605(3) $\AA$, b = 11.8813(3)$\rightarrow$11.6611(4) $\AA$, c = 13.9650(3) $\rightarrow$13.8341(5) $\AA$, $\alpha$ = 73.785(1)$\rightarrow$73.531(2)o, $\beta$ = 74.730(1)→74.903(2)${^{\circ}}$, $\gamma$ = 69.124(1)→ 69.670 $(2){^{\circ}}$, V = 1266.86(5)→1221.53(7) $$\AA^{3}$$, Z = 2. In Ln(III) complexes, three 2,6-DNP ligands coordinate directly to the metal ion in the bidentate fashion. The nine coordinated Ln(III) ion forms slightly distorted tri-capped trigonal prism. There are no water molecules in the crystal lattice. The dependences of metal to ligand bond lengths are discussed on the atomic number of lanthanide elements. The thermal properties of lanthanide complexes of 2,6- DNP have also studied by TG-DTG and DSC thermal analysis methods.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.75-87
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• 1996

Background: Lung cancer is the second most frequent malignancy in man in Korea. Surgery is the best treatment modality for non-small cell lung cancer, but most patients were presented in far advanced stage. So radiation therapy(RT) with or without chemotherapy is the next choice and radiation-induced pneumonitis and pulmonary fibrosis is the major limiting factor for the curative RT. Radiation pneumonitis is manifested with fever, cough and dyspnea, 2~3 months after the termination of radiotherpy. Chest X ray shows infiltration, typically limited to the radiation field, but occasionally bilateral infiltration was reported. Also Gibson et al reported that BAL lymphocytosis was found in both lungs, even though the radiation was confined to one lung. The aim of this study is to investigate the change of adhesion molecules expression on BAL cells and serum soluble ICAM-1(sICAM-1) level after the RT and its relationship to the development of radiation pneumonitis. The second aim is to confirm the bilaterality of change of BAL cell pattern and adhesion molecule expression. Subjects: BAL and the measurement of sICAM level in serum and BALF were done on 29 patients with lung cancer who received RT with curative intention. The BAL was done before the RT in 16 patients and 1~2 month after RT in 18 patients. 5 patients performed BAL before and after RT. Result: Clinically significant radiation pneumonitis developed in 7 patients. After RT, total cell count in BAL was significantly increased from $(20.2{\pm}10.2){\times}10^6\;cells/ml$ to $(35.3{\pm}21.6){\times}10^6\;cells/ml$ (p=0.0344) and %lymphocyte was also increased from $5.3{\pm}4.2%$ to $39.6{\pm}23.4%$ (p=0.0001) in all patient group. There was no difference between ipsilateral and contraleteral side to RT, and between the patients with and without radiation-pneumonitis. In whole patient group, the level of sICAM-1 showed no significant change after RT(in serum: $378{\pm}148$, $411{\pm}150\;ng/ml$, BALF: $20.2{\pm}12.2$, $45.1{\pm}34.8\;ng/ml$, respectively), but there was a significant difference between the patients with pneumonitis and without pneumonitis (serum: $505{\pm}164$ vs $345{\pm}102\;ng/ml$, p=0.0253, BALF: $67.9{\pm}36.3$ vs $25.2{\pm}17.9\;ng/ml$, p=0.0112). The expression of ICAM-1 on alveolar macrophages (AM) tends to increase after RT (RMFI: from $1.28{\pm}0.479$ to $1.63{\pm}0.539$, p=0.0605), but it was significantly high in patients with pneumonitis ($2.10{\pm}0.390$) compared to the patients without pneumonitis ($1.28{\pm}0.31$, p=0.0002). ICAM-1 expression on lymphocytes and CD 18 (${\beta}2$-integrin) expression tended to be high in the patients with pneumonitis but the difference was statiastically not significant. Conclusion: Subclinical alveolitis on the basis of BAL finding developed bilaterally in all patients after RT. But clinically significant pneumonitis occurred in much smaller fraction and the ICAM-1 expression on AM and the sICAM-1 level in serum were good indicator of it.

• Economic and Environmental Geology
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• v.30 no.4
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• pp.303-312
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• 1997

The massive, fractured and porous-type of glauconite, which is subdivided by surface morphology, occur in subtidal sand and semiconsolidated intertidal sand/mud from continental shelf of the southeastern Yellow Sea. This area is presumed to be a part of Holocene transgressive tidal systems tract. The glauconite, pellet-like grains with diameter of 0.1 to 1 mm, is scattered in surface sand sediments. Results of X-ray diffraction data of the minerals are monoclinic with $a=5.242{\AA}$, $b=9.059{\AA}$, $c=10.163{\AA}$, ${\beta}=100.5^{\circ}$, $V=474.53{\AA}^3$. Thermal treatments on the oriented glauconite increase the X-ray diffraction intensity near $10{\AA}$ (001), suggesting the presence of some expandable layers. Specific gravity of the glauconite is $2.60{\pm}0.45gm/cc$ on the basis of chemical composition and unit-cell dimensions. Based on $O_{10}(OH)_2$, chemical composition of glauconites, octahedral Fe content ranges from 1.19 to 2.06 atoms, corresponding octahedral AI is 0.18 to 0.76 atoms, which progressively substitute Fe for AI with increasing from porous to massive-type. The Mg content ranges from 0.35 to 0.54 atoms, and shows higher with increasing Al contents. A systematic increase of interlayer K from 0.34 to 0.71 is also observed with apparent increases from porous to massive-type, and related to a proportion of expandable layers. The clay preserved in glauconite, which is recognized as ordered/disordered (massive to fractured-type). The interstratified illite/smectite (porous-type), contains 7 to 27 % expandable layers. The glauconite seems to originate from post depositional authigenic growth in reducing environments promoted by the dissolution of clay minerals and biogenic debris.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.934-940
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• 1998

Kochujang, fermented hot pepper soybean paste, was prepared by traditional method, and irradiated with gamma ray of $^{60}Co{\;}up{\;}to{\;}15{\pm}1.5{\;}kGy$ for confirming main factor of kochujang fermentation. Nonirradiated (control) and irradiated samples kochujang were fermented at $25^{\circ}C$ and analyzed biochemical properties including enzyme activities and viable cell count during fermentation for 60 days. The total viable count in irradiated kochujang decreased to $10^4{\;}CFU/g$ which was $10^8{\;}CFU/g$ in the control. Because of a little changing enzyme activities of ${\alpha}{\cdot}{\beta}{\;}amylase$ and acid neutral protease by irradiation at the above level, amino type nitrogen which is the main quality reference of kochujang was comparable to the control. By irradiation, gas production was completely stopped which is one of biggest problems during distribution of kochujang. Total volume of gas produced at $25^{\circ}C$ from the control kochujang was 453 mL/100 g which was composed of over 90% of $CO_2$. The odor of irradiated kochujang was inferior to the control which seemed to be related to reduced microbial populations.

• Journal of Korean Dental Science
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• v.10 no.1
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• pp.10-21
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• 2017

Purpose: The purpose of this study was to investigate the electrochemical characteristics of nanotubular Ti-25Nb-xZr ternary alloys for dental implant materials. Materials and Methods: Ti-25Nb-xZr alloys with different Zr contents (0, 3, 7, and 15 wt.%) were manufactured using commercially pure titanium (CP-Ti), niobium (Nb), and zirconium (Zr) (99.95 wt.% purity). The alloys were prepared by arc melting in argon (Ar) atmosphere. The Ti-25Nb-xZr alloys were homogenized in Ar atmosphere at $1,000^{\circ}C$ for 12 hours followed by quenching into ice water. The microstructure of the Ti-25Nb-xZr alloys was examined by a field emission scanning electron microscope. The phases in the alloys were identified by an X-ray diffractometer. The chemical composition of the nanotube-formed surfaces was determined by energy-dispersive X-ray spectroscopy. Self-organized $TiO_2$ was prepared by electrochemical oxidation of the samples in a $1.0M\;H_3PO_4+0.8wt.%$ NaF electrolyte. The anodization potential was 30 V and time was 1 hour by DC supplier. Surface wettability was evaluated for both the metallographically polished and nanotube-formed surfaces using a contact-angle goniometer. The corrosion properties of the specimens were investigated using a 0.9 wt.% aqueous solution of NaCl at $36^{\circ}C{\pm}5^{\circ}C$ using a potentiodynamic polarization test. Result: Needle-like structure of Ti-25Nb-xZr alloys was transform to equiaxed structure as Zr content increased. Nanotube formed on Ti-25Nb-xZr alloys show two sizes of nanotube structure. The diameters of the large tubes decreased and small tubes increased as Zr content increased. The lower contact angles for nanotube formed Ti-25NbxZr alloys surfaces showed compare to non-nanotube formed surface. The corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface showed longer the passive regions compared to non-treatment surface. Conclusion: It is confirmed that corrosion resistance of alloy increased as Zr content increased, and nanotube formed surface has longer passive region compared to without treatment surface.