• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6121-6128
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• 2012

Radiation-induced side effects on normal tissue are determined largely by the capacity of cells to repair radiation-induced DNA damage. X-ray repair cross-complementing group 1 (XRCC1) plays an important role in the repair of DNA single-strand breaks. Studies have shown conflicting results regarding the association between XRCC1 gene polymorphisms (Arg399Gln, Arg194Trp, -77T>C and Arg280His) and radiation-induced side effects in patients undergoing whole breast radiotherapy. Therefore, we conducted a meta-analysis to determine the predictive value of XRCC1 gene polymorphisms in this regard. Analysis of the 11 eligible studies comprising 2,199 cases showed that carriers of the XRCC1 399 Gln allele had a higher risk of radiation-induced toxicity than those with the 399 ArgArg genotype in studies based on high-quality genotyping methods [Gln vs. ArgArg: OR, 1.85; 95% CI, 1.20-2.86] or in studies with mixed treatment regimens of radiotherapy alone and in combination with chemotherapy [Gln vs. ArgArg: OR, 1.60; 95% CI, 1.09-2.23]. The XRCC1 Arg399Gln variant allele was associated with mixed acute and late adverse reactions when studies on late toxicity only were excluded [Gln allele vs. Arg allele: OR, 1.22; 95% CI, 1.00-1.49]. In contrast, the XRCC1 Arg280His variant allele was protective against radiation-induced toxicity in studies including patients treated by radiotherapy alone [His allele vs. Arg allele: OR, 0.58; 95% CI, 0.35-0.96]. Our results suggest that XRCC1 399Gln and XRCC1 280Arg may be independent predictors of radiation-induced toxicity in post-surgical breast cancer patients, and the selection of genotyping method is an important factor in determining risk factors. No evidence for any predictive value of XRCC1 Arg194Trp and XRCC1 -77T>C was found. So, larger and well-designed studies might be required to further evaluate the predictive value of XRCC1 gene variation on radiation-induced side effects in patients undergoing whole breast radiotherapy.

• Imaging Science in Dentistry
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• v.40 no.2
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• pp.69-74
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• 2010

Purpose : The research was performed to predict the three dimensional relationship between the impacted mesiodens and the maxillary central incisors and the proximity with the anatomic structures by comparing their panoramic images with the CT images. Materials and Methods : Among the patients visiting Seoul National University Dental Hospital from April 2003 to July 2007, those with mesiodens were selected (154 mesiodens of 120 patients). The numbers, shapes, orientation and positional relationship of mesiodens with maxillary central incisors were investigated in the panoramic images. The proximity with the anatomical structures and complications were investigated in the CT images as well. Results : The sex ratio (M : F) was 2.28 : 1 and the mean number of mesiodens per one patient was 1.28. Conical shape was 84.4% and inverted orientation was 51.9%. There were more cases of anatomical structures encroachment, especially on the nasal floor and nasopalatine duct, when the mesiodens was not superimposed with the central incisor. There were, however, many cases of the nasopalatine duct encroachment when the mesiodens was superimpoised with the apical 1/3 of central incisor (52.6%). Delayed eruption (55.6%), crown rotation (66.7%) and crown resorption (100%) were observed when the mesiodens was superimposed with the crown of the central incisor. Conclusion : It is possible to predict three dimensional relationship between the impacted mesiodens and the maxillary central incisors in the panoramic images, but more details should be confirmed by the CT images when necessary.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1754-1758
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• 2002

Tetrathiafulvalene(TTF) reacts with $PdCl_2,Pd(NO_3)_2$ and $Pd(hfacac)_2$(hexafluoroacetylacetonate) in ethanol to give $(TTF)_{1.5}PdCl_2$ (1a), $(TTF)_3Pd(NO_3)_2$ (1b) and $(TTF)_4Pd(hfacas)_2$ nd (1c), respectively. $PdCl(TCNQ)_{2.5}{\cdot}CH_3OH(2a)$was obtained from the reaction of $PdCl_2$ with LiTCNQ in methanol via the partial replacement of $Cl^-$ in $PdCl_2$ by $TCNQ^-$anion, whereas the total substitution of the labile $NO_3^-$ in $Pd(NO_3)_2$ yielded pd(TCNQ)·$CH_3OH$ (2b). $Pd(hfacac)_2(TCNQ)_2\cdot3CH_3OH$ (2c) was obtained from $Pd(hfacac)_2$ and LiTCNQ in methanol. The prepared compounds were characterized by spectroscopic (IR, UV, XPS) methods and magnetic (EPR, magnetic susceptibility) studies. The powdered electrical conductivities (${\sigma}_{rt}$) of the prepared compounds at room temperature were about~$10^{-7}S{\cdot}cm^{-1}$. The effective magnetic moments were lass than the spin-only value of one unpaired electron and no EPR signals from Pd metal ions were observed in any of the compounds, indicating that the Pd ions were diamagnetic and the magnetic moments arose from$(TTF)_n$ or $(TCNQ)_n$ moieties. The experimental evidences revealed that the charge transfer had occurred form $(TTF)_n$ moiety to the central Pd metal ion in 1a, 1b and 1c. Thus the TTF donors were ions in 2a and 2b were diamagnetic Pd(II) oxidation state. In contrast, the Pd metal ion was oxidized to Pd(IV) state in 2c as a result of an addition of $TCNQ^-$anion to $Pd(hfacac)_2$ in methanol. The oxidation states of the Pd metal ions were confirmed using the x-ray photoelectron spectroscopy.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.4
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• pp.303-312
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• 2023

The determination of the oxidation states of metal elements in manganese nodules sheds light on the understanding of the formation mechanism of nodules, providing insights into the paleo-environmental conditions such as the redox potential of the aqueous system. This study aims to reveal the oxidation states and chemical bonding of manganese in the natural polymetallic nodules, utilizing conventional X-ray photoelectron spectroscopy (XPS). Specifically, shallow manganese nodules from the Siberian Arctic Sea, effectively recording mineralogical variations, were used in this study. Detailed analysis of XPS Mn 2p spectra showed changes in the manganese oxidation state from the center to the outer parts of the nodules. The central part of the nodules showed a higher Mn⁴⁺ content, approximately 67.9%, while the outermost part showed about 63% of Mn⁴⁺ due to an increase in the Mn³⁺+Mn²⁺. The decrease in the Mn oxidation state with the growth is consistent with the previously reported mineralogical variations from todorokite to birnessite with growth. Additionally, the O 1s spectra presented a predominance of Mn-O-H bonds in the outer layers compared to the center, suggesting hydration by water in the layered manganates of outer layers. The results of this study demonstrate that XPS can be directly applied to understand changes in paleo-environmental conditions such as the redox states during the growth of manganese nodules. Finally, future studies using high-resolution synchrotron-based XPS experiments could achieve details in oxidation states of manganese and trace metal elements.

• The Korean Journal of Nuclear Medicine
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• v.24 no.2
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• pp.229-236
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• 1990

Perfusion and ventilaion imagings of the lung are well established procedure for diagnosing pulmonary embolism, differentiation it from chronic obstructive lung disease, and making an early detection of chronic obstructive lung disease. To evaluate the usefulness of radioaerosol inhalation imaging (RII) in chronic obstructive lung disease, especially pulmonary emphysema, we analyzed RIIs of five normal adult non-smokers, five asymptomatic smokers (age 25-42 years with the mean 36), and 21 patients with pulmonry emphysema (age 59-78 years with the mean 67). Scintigrams were obtained with radioaerosol produced by a BARC nebulizer with 15 mCi of Tc-99m-phytate. Scanning was performed in the anterior, posterior, and lateral projections after five to 10-minute inhalation of the radioaerosol on sitting position. The scans were analyzed and correlated with the results of pulmonary function studies and chest radiographs. Also lung perfusion scan with $^{99m}Tc-MAA$ was performed in 12 patients. In five patients, we performed follow-up scans for the evaluation of the effects of a bronchodilator. Based on the X-ray findings and clinical symptoms, pulmonary emphysema was classified into four types: centrilobular (3 patients), panlobular (4 patients), intermediate (10 patients), and combined (4 patients). RII findings were patternized according to the type, extent, and intensity of the aerosol deposition in the central bronchial and bronchopulmonary system and lung parenchyma. 10 controls, normal five non-smokers and three asymptomatic smokers revealed homogeneous parenchymal deposition in the entire lung fields without central bronchial deposition. The remaining two of asymptomatic smokers revealed mild central airway deposition. The great majority of the patients showed either central (9/21) or combined type (10/21) of bronchopulmonary deposition and the remaining two patients peripheral bronchopulmonary deposition. Parenchymal aerosol deposition in pulmonary emphysema was diffuse (6/21), discrete(6/21), intermediate (3/21), or combined (6/21). In 12 patients studied also with perfusion scans, perfusion defects matched closely with ventilation defects in location and configuration. But the size of the ventilation defects was generally larger than the perfusion defects. In all four patients treated with bronchodilators, the follow-up study demonstrated decrease in abnormal of radioaerosol deposition in the central airway with improvement of ventilation defects. RII was useful technique for the evaluation of regional ventilatory abnormality and the effects of treatment with bronchodilators in pulmonary emphysema.

• Radiation Oncology Journal
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• v.6 no.1
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• pp.85-91
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• 1988

For the physical characterization of neutron beam, dosimetric measurements had been performed to obtain physical data of KCCH cyclotron-produced neutrons for clinical use. The results are presented and compared with the data of other institutions from the literatures. The central axis percent depth dose, build-up curves and open and wedge isodose curve values are intermediate between that of a 4 and 6 MV X-rays. The build-up level of maximum dose was at 1.35cm and entrance dose was approximately $40\%$. Flatness of the beam was $9\%$ at Dmax and less $than{\pm}3\%$ at the depth of $80\%$ isodose line. Penumbra begond the $20\%$ line is wider than corresponding photon beam. The output factors ranged 0.894 for $6\times6cm$ field to 1.187 for $30\times30cm$ field. Gamma contamination of neutron beam was $4.9\%$ at 2 cm depth in $10\times10cm$ field.

• Korean Journal of Materials Research
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• v.18 no.11
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• pp.623-627
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• 2008

For possible applications as luminescent materials for white-light emission using UV-LEDs, $Ba_2Mg(PO_4)_2:Eu^{2+}$ phosphors were prepared by a solid state reaction. The photoluminescence properties of the phosphor were investigated under ultraviolet ray (UV) excitation. The prepared phosphor powders were characterized to from a single phase of a monoclinic crystalline structure by a powder X-ray diffraction analysis. In the photoluminescence spectra, the $Ba_2Mg(PO_4)_2:Eu^{2+}$ phosphor showed an intense emission band centered at the 584 nm wavelength due to the f-d transition of the $Eu^{2+}$ activator. The optimum concentration of $Eu^{2+}$ activator in the $Ba_2Mg(PO_4)_2$ host, indicating the maximum emission intensity under the excitation of a 395 nm wavelength, was 5 at%. In addition, it was confirmed that the $Eu^{2+}$ ions are substituted at both $Ba^{2+}$ sites in the $Ba_2Mg(PO_4)_2$ crystal. On the other hand, the critical distance of energy transfer between $Eu^{2+}$ ions in the $Ba_2Mg(PO_4)_2$ host was evaluated to be approximately 19.3 A. With increasing temperature, the emission intensity of the $Ba_2Mg(PO_4)_2$:Eu phosphor was considerably decreased and the central wavelength of the emission peak was shifted toward a short wavelength.

• Imaging Science in Dentistry
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• v.34 no.1
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• pp.7-12
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• 2004

Purpose: To investigate the anatomical structure of the incisive canal radiographically by a cone beam computed tomography. Materials and Methods: 38 persons (male 26, female 12) were chosen to take images of maxillary anterior region in dental CT mode using a cone beam computed tomography. The tube voltage were 65, 67, and 70kVp, the tube current was 7 mA, and the exposure time was 13.3 seconds. The FH plane of each person was parallel to the floor. The images were analysed on the CRT display. Results: The mean length of incisive canal was 15.87 mm±2.92. The mean diameter at the side of palate and nasal fossa were 3.49 mm±0.76 and 3.89 mm± 1.06, respectively. In the cross-sectional shape of incisive canal, 50% were round, 34.2% were ovoid, and 15.8% were lobulated. 87% of incisive canal at the side of nasal fossa have one canal, 10.4% have two canals, and 2.6% have three canals, but these canals were merged into one canal in the middle portion of palate. The mean angles of the long axis of incisive canal and central incisor to the FH plane were 110.3°±6.96 and 117.45°±7.41, respectively. The angles of the long axis of incisive canal and central incisor to the FH plane were least correlated (r= 0.258). Conclusion : This experiment suggests that a cone beam computed radiography will be helpful in surgery or implantation on the maxillary incisive area.

• Conservation and Restoration of Cultural Heritage
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• v.1 no.1
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• pp.9-22
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• 2012

The most widely excavated iron artifacts used as weapons or farm tools from central southern regions of Korea were subjects of non-metallic inclusion analysis through metallographic examination, microhardness measurement, and scanning electron microscopy with energy dispersive X-ray spectroscopy. Through metallographic interpretation and study of the analyzed results, the steel manufacturing and iron smelting using heat processing in the iron artifacts excavated from the central southern region of the ancient Korean peninsula was studied, and the analysis of the non-metallic inclusions mixed within the metallic structures was interpreted as the ternary phase diagram of the oxide to infer the type of iron ores for the iron products and the temperature of the furnace used to smelt them. Most of the ancient forged iron artifacts showed $Al_2O_3/SiO_2$ with high $SiO_2$ contents and relatively low $Al_2O_3$ contents for iron ore, indicating t hat for $Al_2O_3$ below 5%, it is presumed that magnetic iron ores were reduced to bloom iron (sponge iron) with direct-reduction process for production. The temperature for extraction of wustite for $Al_2O_3$ below 1% was found to be $1,020{\sim}1,050^{\circ}C$. Considering the oxide ternary constitutional diagram of glassy inclusions, the steel-manufacturing temperature was presumed to have been near $1,150{\sim}1,280^{\circ}C$ in most cases, and minimum melting temperature of casting iron part excavated in Daeseong-ri. Gyeonggi was near $1,400^{\circ}C$, and it is thought that hypoeutectic cast iron of about 2.3% carbon was casted and fragility of cast iron was improved by decarburizing in solid state.

• Journal of Chest Surgery
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• v.33 no.1
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• pp.7-19
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• 2000

Background :To assess the accuracy of Electron-Beam Tomography(EBT) in following evaluation of the pulmonary vascular system after a shunt operation in the cyanotic con-genital heart disease with pulmonary stenosis or pulmonary atresia. Material and Method : Sixteen patients(M:F=11:5) who received Blalock-Taussig(n=8) bidirectional cavo-pulmonary shunt(n=10) and unifocalization (n=2) were ncluded in the study. We evaluated the patency of the shunt the morphology of intrapericardial and hilar pulmonary arteries(PA) peripheral pulmonary vascularity by background lung attenuation and the abundance of arterial & venous collateral. Angiography(n=12) and echocardiography(n=20) were used as the gold standard for the comparison of EBT results. Result: EBT was consistent with angiogram/ echo in 100% of the evaluation for the patency of the shunt and in 12(by angiogram 100%) and 19(by echo 95%) for the detection the hypoplasia stenosis or interruption of central PA In measuring of PA EBT and angiogram corrlated(r=0.91) better than EBT-echo(r=0.88) or echo-angiogram(r=0.72) Abundant systemic arterial collateral were noted in 4 and venous collateral in 3 cases. In evaluating the peripheral pulmonary vascularity the homogenous and normal-ranged lung attenuation(m=6) decreased but homo-genous attenuation(n=1) segment-by-sgment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) segment-by-segment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) and venous congestion(n=2) were observed nd 12 of them were compatible with the blood flow pattern revealed by cardiac catheterization. Conclusion: EBT was accurate in the integrated evaluation of the pulmonary vascular system after the shunt including the patency of the shunt operaion the morphology and dimension of the central and hilar PAs and the loco-regional pulmonary flow in the lung parenchyma. It suggests the useful information about the need of secondary shunt operation the proper timing time for total repair and the need of interventional procedure prior to total repair.