• Journal of the Mineralogical Society of Korea
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• v.27 no.1
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• pp.1-15
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• 2014

Probing the electronic structures of crystalline Mg-silicates at high pressure is essential for understanding the various macroscopic properties of mantle materials in Earth's interior. Quantum chemical calculations based on the density functional theory are used to explore the atomic configuration and electronic structures of Earth materials at high pressure. Here, we calculate the partial density of states (PDOS) and O K-edge energy-loss near-edge structure (ELNES) spectra for $MgSiO_3$ perovskite at 25 GPa and 120 GPa using the WIEN2k program based on the full-potential linearized projected augmented wave (FP-LPAW) method. The calculated PDOS and O K-edge ELNES spectra for $MgSiO_3$ Pv show significant pressure-induced changes in their characteristic spectral features and relative peak intensity. These changes in spectral features of $MgSiO_3$ Pv indicate that the pressure-induced changes in local atomic configuration around O atoms such as Si-O, O-O, and Mg-O length can induce the significant changes on the local electronic structures around O atoms. The result also indicates that the significant changes in O K-edge features can results from the topological densification at constant Si coordination number. This study can provide a unique opportunity to understand the atomistic origins of pressure-induced changes in local electronic structures of crystalline and amorphous $MgSiO_3$ at high pressure more systematically.

• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1107-1115
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• 2005

Purpose : An outbreak of ESBL-producing Shigella sonnei enteritis was unprecedented not only in Korea but throughout the world in the past. We intended to devise a management guideline for ESBL-producing shigellosis based on analysis of clinical manifestations and response to therapy. Methods : We analyzed 103 patients who were admitted to the hospital with acute GI symptoms and were shown positive result for S. sonnei on stool culture. We performed sensitivity test to the antibiotics and DNA sequencing of ESBL gene in the isolated S. sonnei colonies. In addition, we retrospectively analyzed their clinical characteristics, laboratory results, and clinical and microbiological responses to the antibiotics. Results : Among the clinical manifestations, fever was the most frequent(96.1%), followed by diarrhea(93.2%), abdominal pain(76.7%), headache(71.8%), vomiting(65.0%), and nausea(41.7%). The fever was sustained for average of 2.0 days and diarrhea for 3.9 days. Watery diarrhea was the most common(69%) followed by mucoid(26%), and bloody stool(5%). On peripheral blood smear, leukocytosis was noted in 53.4% of patients, and 78.6% of patients tested positive for serum CRP response. On stool direct smear, 11.7% of patients showed more than 50 WBCs/HPF, and 9.7% of patients between 5 to 20 WBCs/HPF. Stool occult blood was positive in 71% of patients. Production of CTX-M-14 type ESBL was reported for all S. sonnei strains isolated from this outbreak. Microbiological eradication rates to various antibiotics were as follows : 100%(9/9) to ciprofloxacin, 100% 5/5) to azithromycin, 6.9%(5/72) to cefdinir, 0%(0/8) to ceftriaxone, 12.5%(1/8) to ceftizoxime, 0%(0/ 8) to TMP/SMX, 42.9%(3/7) to ampicillin/sulbactam, 20%(1/5) to amoxicillin/clavulanic acid, and 68.8 %(11/16) to imipenem/cilastatin. Conclusion : It is presumed that azithromycin can be an attractive option for the treatment of ESBL-producing S. sonnei enteritis in pediatric population, given its cost-effectiveness and safety. Although ciprofloxacin is another cost-effective agent, its use in pediatric population may be a bit too premature.

• Journal of the Mineralogical Society of Korea
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• v.30 no.2
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• pp.59-70
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• 2017

$SiO_2$ is one of the most abundant constituents of the Earth's crust and mantle. Probing its electronic structures at high pressures is essential to understand their elastic and thermodynamic properties in the Earth's interior. The in situ high-pressure x-ray Raman scattering (XRS) experiment has been effective in providing detailed bonding transitions of the low-z materials under extreme compression. However, the relationship between the local atomic structures and XRS features at high pressure has not been fully established. The ab initio calculations have been used to overcome such experimental difficulties. Here we report the partial density of states (PDOS) of O atoms and the O K-edge XRS spectra of ${\alpha}-quartz$, ${\alpha}-cristobalite$, and $CaCl_2$-type $SiO_2$ phases calculated using ab initio calculations based on the full-potential linearized augmented plane wave (FP-LAPW) method. The unoccupied O PDOSs of the $CaCl_2$-type $SiO_2$ calculated with and without applying the core-hole effects present significantly distinctive features. The unoccupied O p states of the ${\alpha}-quartz$, ${\alpha}-cristobalite$ and $CaCl_2$-type $SiO_2$ calculated with considering the core-hole effect present similar features to their calculated O K-edge XRS spectra. This confirms that characteristic features in the O K-edge XRS stem from the electronic transition from 1s to unoccupied 2p states. The current results indicate that the core-hole effects should be taken in to consideration to calculate the precise O K-edge XRS features of the $SiO_2$ polymorphs at high pressure. Furthermore, we also calculated O K-edge XRS spectrum for $CaCl_2$-type $SiO_2$ at ~63 GPa. As the experimental spectra for these high pressure phases are not currently available, the current results for the $CaCl_2$-type $SiO_2$ provide useful prospect to predict in situ high-pressure XRS spectra.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.625-636
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• 2010

The geophysical characteristics and geological structure of the northeastern part of the Ulleung Basin were investigated from interpretation of geophysical data including gravity, magnetic, bathymetry data, and seismic data. Relative correction was applied to reduce errors between sets of gravity and magnetic data, obtained at different times and by different equipments. The northeastern margin of the Ulleung Basin is characterized by complicated morphology consisting of volcanic islands (Ulleungdo and Dokdo), the Dokdo seamounts, and a deep pathway (Korea Gap) with the maximum depth of -2500 m. Free-air anomalies generally reflect the topography effect. There are high anomalies over the volcanic islands and the Dokdo seamounts. Except local anomalous zones of volcanic edifices, the gradual increasing of the Bouguer anomalies from the Oki Bank toward the Ulleung Basin and the Korea Gap is related to higher mantle level and denser crust in the central of the Ulleung Basin. Complicated magnetic anomalies in the study area occur over volcanic islands and seamounts. The power spectrum analysis of the Bouguer anomalies indicates that the depth to the averaged Moho discontinuity is -16.1 km. The inversion of the Bouguer anomaly shows that the Moho depth under the Korea Gap is about -16~17 km and the Moho depths towards the Oki Bank and the northwestern part of Ulleung Island are gradually deeper. The inversion result suggests that the crust of the Ulleung Basin is thicker than normal oceanic crusts. The result of 20 gravity modeling is in good agreement with the results of the power spectrum analysis and the inversion of the Bouguer anomaly. Except the volcanic edifices, the main pattern of magnetization distribution shows lineation in NE-SW. The inversion results, the 2D gravity modeling, and the magnetization distribution support possible NE-SW spreading of the Ulleung Basin proposed by other papers.

• Journal of the Mineralogical Society of Korea
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• v.24 no.4
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• pp.289-300
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• 2011

Atomistic origins of carbon solubility into silicates are essential to understand the effect of carbon on the properties of silicates and evolution of the Earth system through igneous and volcanic processes. Here, we investigate the atomic structure and NMR properties of dissolved carbon in enstatite using Raman spectroscopy and quantum chemical calculations. Raman spectrum for enstatite synthesized with 2.4. wt% of amorphous carbon at 1.5 GPa and $1,400^{\circ}C$ shows vibrational modes of enstatite, but does not show any vibrational modes of $CO_2$ or ${CO_3}^{2-}$. The result indicates low solubility of carbon into enstatite at a given pressure and temperature conditions. Because $^{13}C$ NMR chemical shift is sensitive to local atomic structure around carbon and we calculated $^{13}C$ NMR chemical shielding tensors for C substituted enstatite cluster as well as molecular $CO_2$ using quantum chemical calculations to give insights into $^{13}C$ NMR chemical shifts of carbon in enstatite. The result shows that $^{13}C$ NMR chemical shift of $CO_2$ is 125 ppm, consistent with previous studies. Calculated $^{13}C$ NMR chemical shift of C is ~254 ppm. The current calculation will alllow us to assign potential $^{13}C$ NMR spectra for the enstatite dissolved with carbon and thus may be useful in exploring the atomic environment of carbon.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.516-526
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• 2003

Thirty-six barley varieties including Korean modern and local varieties were tested for drought-tolerance in the field of plastic rain shelter, Drought treatment was initiated at initial tillering stage (March 27, 2002) by withholding irrigation and lasted until harvest. Soil water potential maintained at around -0.05㎫ in the control plot and varied from -0.05㎫ (at the initial stage of drought treatment) to -0.29㎫ in the drought treatment plot. At forty days after drought treatment, relative water content (RWC), osmotic potential (OP), osmotic adjustment (OA), and $^{13}\textrm{C}$ discrimination ($\Delta$) were measured and then plants were sampled for leaf area index (LAI) and dry weight (DW). Barley was harvested at maturity for determining DW, grain yield, 1000 grains weight and number of spikelet. The tested varieties revealed wide spectrum of drought tolerance. Dongbori-1, Chalbori, Changyeongjaerae, Samdobori and Weolseong 87-31 showed strong drought-tolerance while Songhagbori and Suwonmaeg360 showed weak drought-tolerance. The drought injury indexes (drought/control ratio) of DW and yield revealed significant positive correlation with leaf RWC in drought treatment plot and $\Delta$ in the control plot, but obvious negative correlation with leaf OP and OA under drought condition. In addition, all the drought indexes of OP, $\Delta$ and RWC showed obvious positive correlation with the drought injury indexes of DW, 1000 grain weight and yield. Thus, OP and RWC under drought condition and $\Delta$ under well-watered condition would be used as the evaluation criteria for drought- tolerance of barley genotypes. However, further investigation is needed for the relationship between $\Delta$ and drought-tolerance as the other reports were not consistent with our result.

• Journal of Acupuncture Research
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• v.18 no.3
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• pp.154-170
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• 2001

Objective : To broaden understanding about acupuncture and moxibustion therapy on AIDS and to promote base studies and clinical trials Materials and Methods : Analysis was given to more than 30 literatures including acupuncture and moxibustion therapy on AIDS-related sites explored by internet search engine named NAVER from Nov., 2000 to Feb. 20th, 2001 Results : 1. Acupuncture and moxibustion played great role as a complementary therapy in enabling AIDS patients to keep their antiretroviral therapy by enhancing immune system, ameliorating AIDS-related symptoms and side effect of antiretroviral drug 2. Acupuncture and moxibustion therapy had a broad spectrum indication from systemic or local signs of AIDS patients to signs of antiretroviral drug-related side effect 3. Contraindication of acupuncture and moxibustion therapy against AIDS patients include abstraction and moxibustion on the skin lesion, because of their easy exposure to inflammation 4. AIDS patients were regarded as the state of KI-HE(氣虛), EUM-HE(陰虛), YEOL-DOK(熱毒) in general 5. BO-KI(補氣), BO-HYUL(補血), BO-EUM(補陰), CHEONG-YEOL-HAE-DOK(淸熱解毒) were shown as a principle of acupuncture and moxibustion therapy for AIDS patients 6. Principle of selecting acupoints for AIDS patients had characteristics of enhancing immune system, detoxicating detrimental agents and relieving each AIDS related symptom appropriately 7. Acupuncture on 合谷(HAPKOK, LI4), 內關(NAE-GWAN, P6), 足三里(CHOK-SAMNI, S36) were applied to the early stage of AIDS in order to enhance immune system. Acupuncture on 血海(HYOLHAE, SP10), 三陰交(SAMUMGYO, SP6), (KOHWANG, B43) were applied to the intermediate stage of AIDS so as to enhance immune system and eliminate YEOL-DOK(熱毒) in blood. Moxibustion on 湧泉(YONGCHON, K1), 足三里(CHOK-SAMNI, S36) were applied to the late stage owing to enhance immune system more. Conclusion : The efficacy of acupuncture and moxibustion therapy on AIDS has been acknowledged to the world, moreover, it is proved to be significant as a complementary therapy on AIDS patients. Thus, more control group studies of the efficacy of acupuncture and moxibustion therapy on AIDS and clinical trials are considered to be necessary.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1131-1131
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• 2001

To develop a nondestructive quality evaluation technique of fruits, a K-mean algorism is applied to near infrared (NIR) spectroscopy of apples. The K-mean algorism is one of neural network partition methods and the goal is to partition the set of objects O into K disjoint clusters, where K is assumed to be known a priori. The algorism introduced by Macqueen draws an initial partition of the objects at random. It then computes the cluster centroids, assigns objects to the closest of them and iterates until a local minimum is obtained. The advantage of using neural network is that the spectra at the wavelengths having absorptions against chemical bonds including C-H and O-H types can be selected directly as input data. In conventional multiple regression approaches, the first wavelength is selected manually around the absorbance wavelengths as showing a high correlation coefficient between the NIR $2^{nd}$ derivative spectrum and Brix value with a single regression. After that, the second and following wavelengths are selected statistically as the calibration equation shows a high correlation. Therefore, the second and following wavelengths are selected not in a NIR spectroscopic way but in a statistical way. In this research, the spectra at the six wavelengths including 900, 904, 914, 990, 1000 and 1016nm are selected as input data for K-mean analysis. 904nm is selected because the wavelength shows the highest correlation coefficients and is regarded as the absorbance wavelength. The others are selected because they show relatively high correlation coefficients and are revealed as the absorbance wavelengths against the chemical structures by B. G. Osborne. The experiment was performed with two phases. In first phase, a reflectance was acquired using fiber optics. The reflectance was calculated by comparing near infrared energy reflected from a Teflon sphere as a standard reference, and the $2^{nd}$ derivative spectra were used for K-mean analysis. Samples are intact 67 apples which are called Fuji and cultivated in Aomori prefecture in Japan. In second phase, the Brix values were measured with a commercially available refractometer in order to estimate the result of K-mean approach. The result shows a partition of the spectral data sets of 67 samples into eight clusters, and the apples are classified into samples having high Brix value and low Brix value. Consequently, the K-mean analysis realized the classification of apples on the basis of the Brix values.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.2
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• pp.131-139
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• 2008

Purpose: Lipomatous tumor occurred in hand is very rare. There is a broad spectrum of lipomatous tumors including lipomas, variants of lipomas, lipomatosis, liposarcomas and so on. We report the clinical features of 11 cases of lipomatous tumor which occurred in hand. Materials and Methods: Between 1992 and 2008, 11 cases were histologically diagnosed as lipomatous tumor in hand. We reviewed all medical records and clinical photographs retrospectively and ascertained recurrence by telephone interview. Results: Eight cases were ordinary lipomas. Three cases were angiolipoma, fibrolipoma and atypical lipoma respectively. Four cases occurred in finger, two cases in thenar area, two cases in hypothenar area, one case in palm, two cases in wrist. All cases were situated on volar surface. All patients complained of palpable masses. One patient with subungal angiolipoma felt pain. There was no neurologic sign or vascular symptom preoperatively. In one case, postoperative complication (hypoesthesia in $5^{th}$ finger) was developed. There was no local recurrence. Conclusion: In our study, lipomatous tumors occurred in hand did not recur. Patients mainly complained of feeling of lump. Pain was uncommon symptom. Postoperative complication was rare if operation was performed carefully.

• Journal of the Korean earth science society
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• v.31 no.6
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• pp.541-554
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• 2010

Fifteen min-microtremor data sets were collected at 136 sites from a coastal area of Kunsan and 117 sites from an inland area of Jeonju located in SW Korea, and were analyzed for the HVSR (Horizontal to Vertical Spectral Ratio) of the sites. The microtremor spectra of the coastal area have stronger energy in the lower frequency range from 1-6 Hz than those of the coastal area. This result can be attributed to the effect of the waves and tides in the Keum river and the Yellow sea. Twenty four hours of measurement of the microtremor indicated that the microtremor spectrum correlates with the human activities, but the microtremor HVSR peak was observed consistently at the characteristic frequency for the site. The HVSR peaks were grouped into 4 types -"single peak", "double peak", "broad peak" or "no peak"- based on their shapes. More than 90% of the data sets exhibit peak frequencies ($F_0$) which can be easily identified. The distribution of $F_0$ reveals a close relationship with the topography and local geology of the areas, exhibiting high F0s in the hillside areas and low $F_0s$ in the reclaimed land area. While the amplitudes of microtremor HVSR peak frequencies are less than 4 in the downstream of the inland area, those of the recently reclaimed land in the coastal area are extremely high (more than 10). The results of this study indicate that detailed HVSR studies are essential for the earthquake hazard reduction of reclaimed lands.