• Economic and Environmental Geology
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• v.42 no.3
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• pp.167-175
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• 2009

The geology of Sepola district in Mali is consisted of Birrimian group with metasedimentary rocks of lower Proterozoic and volcanoclastics, and later intrusive igneous rocks. Ore diposit in this district has the characteristics of vein- and disseminated-type gold deposit which was formed by infilling the secondary fracture zones related to the large-scale fault zone of NW direction within Birrimian group. It is confirmed as promising that Barani district has the gold grade of 0.53${\sim}$9.21 g/t with the extension of 1.3 km and width of 1 to 20.1 m. The ore mineralogy is simple with electrum, pyrite and galena. Fineness of gold grain ranges from 848 to 915(average 891) indicating mesothermal to hypothermal environment. Fluid inclusions are classified as liquid-rich type I. gas-rich type II and liquid-$CO_2$ bearing type III. Primary and pseudosecondary inclusions homogenize from 236 to 393$^{\circ}C$ with salinity of 0.0 to 8.6 wt% NaCl. Secondary inclusions homogenize from 103 to 184$^{\circ}C$ with salinity of 0.7 to 8.6 wt.%. From the relationship between homogeniztion temperature and salinity, it may be thought that auriferous fluid experienced dilution and cooling through inflow of meteoric water after fluid unmixing derived from pressure decrease in the temperature range of 400 to 250$^{\circ}C$. From the massive occurrence of quartz vein, simple mineralogy with paucity of sulfide, and presence of liquid-$CO_2$ bearing with high homogenization temperature, it is thought that gold mineralization in Sepola district correspods to the mesothermal to hypothermal ore deposit.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.278-288
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• 2011

This study was conducted to evaluate the safety of ${\beta}$-carotene biofortified rice, a genetically modified organism (GMO) developed by Rural Development Administration. ${\beta}$-carotene biofortified rice were exposed on Sprague-Dawley rats for 13 weeks. All rats survived until the end of the exposure period. There were no biologically significant differences in body weight, feed and water consumption, weight gains and feed efficiency. There were no clinical signs of toxicity attributable to exposure to GM rice. Mild decreases in AST, ALT, TG levels were observed in Group II (25% GM rice (w/w) and Group III (50% GM rice (w/w), both in females and males. Results of histopathological changes treated with the ${\beta}$-carotene biofortified rice had no significant differences between the control and treatment groups. Based on these results, we deemed that genetically modified ${\beta}$-carotene biofortified rice was as safe as conventional rice.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.303-311
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• 2017

In this study, random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) analyses were used for evaluation of genetic diversity of 61 kiwifruit (Actinidia spp.) germplasms including domestic and overseas collection cultivars. Forty RAPD primers were detected in a total of 230 polymorphic bands with an average of 5.75. Thirty-two SRAP primer combinations were detected in a total of 204 polymorphic bands with an average 6.38. By unweighted pair-group method arithmetic average cluster analysis using 434 polymorphic bands, kiwifruit germplasms were classified in three groups with similarity value of 0.680. Cluster I consisted of 46 kiwifruit germplasms belonging to A. deliciosa, A. chinensis, A. deliciosa ${\times}$ A. arguta, A. chinensis ${\times}$ A. arguta, and A. chinensis ${\times}$ A. deliciosa. Cluster II consisted of seven germplasms belonging to A. arguta and 'Skinny Green', a cultivar derived from a cross between A. arguta and A. deliciosa. Cluster III consisted of seven germplasms belonging to A. rufa, A. hemsleyana, A. macrosperma, A. polygama, and A. eriantha. Genetic similarity values among tested kiwifruit germplasms ranged from 0.479-0.991, and average similarity value was 0.717. Similarity value was highest (0.991) between NHK0038 (A. deliciosa) and NHK0040 (A. deliciosa), and lowest (0.479) between 'Hayward' (A. deliciosa) and K5-1-22 (A. arguta).

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.120-120
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• 1998

Boron nitride (BN) films have attracted a growing interest for a variety of t technological applications due to their excellent characteristics, namely hardness, c chemical inertness, and dielectrical behavior, etc. There are two crystalline phases 1551; of BN that are analogous to phases of carbon. Hexagonal boron nitride (h-BN) has a a layered s$\sigma$ucture which is spz-bonded structure similar to that of graphite, and is t the stable ordered phase at ambient conditions. Cubic boron nitride (c-BN) has a z zinc blende structure with sp3-bonding like as diamond, 따ld is the metastable phase a at ambient conditions. Among of their prototypes, especially 삼Ie c-BN is an i interesting material because it has almost the same hardness and thermal c conductivity as di없nond. C Conventionally, significant progress has been made in the experimental t techniques for synthesizing BN films using various of the physical vapor deposition 밍ld chemical vapor deposition. But, the major disadvantage of c-BN films is that t they are much more difficult to synthesize than h-BN films due to its narrow s stability phase region, high compression stress, and problem of nitrogen source c control. Recent studies of the metalorganic chemical vapor deposition (MOCVD) of I III - V compound have established that a molecular level understanding of the d deposition process is mandatory in controlling the selectivity parameters. This led t to the concept of using a single source organometallic precursor, having the c constituent elements in stoichiometric ratio, for MOCVD growth of 삼Ie required b binary compound. I In this study, therefore, we have been carried out the growth of h-BN thin f films on silicon substrates using a single source precursors. Polycrystalline h-BN t thin films were deposited on silicon in the temperature range of $\alpha$)() - 900 $^{\circ}$C from t the organometallic precursors of Boron-Triethylamine complex, (CZHs)3N:BRJ, and T Tris(dimethylamino)Borane, [CH3}zNhB, by supersonic molecular jet and remote p plasma assisted MOCVD. Hydrogen was used as carrier gas, and additional nitrogen w was supplied by either aDlIDonia through a nozzle, or nitrogen via a remote plasma. T The as-grown films were characterized by Fourier transform infrared spectroscopy, x x-ray pthotoelectron spectroscopy, Auger electron spectroscopy, x-ray diffraction, t transmission electron diffraction, optical transmission, and atomic force microscopy.roscopy.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.509-513
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• 2010

Recently, an amount of waste electronic devices such as LED and trichromatic fluorescent lamp has increased with the development of electronic industry. Reportedly, rare earth metals such as yttrium and europium have been discovered in the waste electronic devices. In order to improve the selectivity of yttrium and europium, the effects of the following factors on recovery experiment have been considered : i) fatty acids with various alkyl chain lengths, ii) the concentration of extractant, and iii) pH. The results show that the extraction efficiencies decrease at the same pH with decreasing the concentration of extractant and so $pH_{0.5}$ (That value of pH in an aqueous phase at which the distribution ratio is unity at equilibrium: 50% of the solute is extracted (E = 0.5) only when the phase ratio is unity.) moves into higher pH. The highest selectivity of yttrium and europium was obtained with tetradecanoic acid as extractant. The extraction mechanism of yttrium and europium was varied with the change of concentration of the tetradecanoic acid. $MR_3$single-species was formed from the yttrium and europium ion in the extractant concentration less than 0.1 M. On the other hand, the yttrium or europium ion is solvated with three molecules of tetradecanoic acid monomer like $MR_3{\cdot}$ 3RH in the extractant concentration more than 0.1 M.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.465-474
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• 2017

This study aimed to identify the trends of related research as a basic study for the development of creative convergent formative education program of natural structure concept. This study sought to identify research trends present in previous studies. The nature structure of the preliminary research was limited to the three concepts: (i) fractal ; (ii) kinetic and (iii) biomimicry. In this study, the trends of domestic research in the last 10 years related to the concept of natural structure were analyzed using academic research information service. It was found that, to date, little research has been conducted on the three concepts across education fields. In relation to the fractal concept, previous research has focused on mathematics. This preliminary study sought to review the abovementioned three concepts or the development of a modeling education program. It should be significant, if an education program adopted unlimited modeling principles to understand the innate features of the nature structure. However, very few education programs have adopted the three concepts of the nature structure. Future studies would seek to review international research trends based on the three concepts of the nature structure and combine the results on international research trends with the results on domestic research trends found in this study.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.235-240
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• 2007

AvrRpt2 protein triggers hypersensitive response (HR) and strong disease resistance when it is translocated from a bacterial pathogen Pseudomonas sp. to host plant cells containing a cognate RPS2 resistance protein through Type III Secretion System (TTSS). However, AvrRpt2 protein can function as the effector that suppresses a basal defense and enhances the disease symptom when functional RPS2 resistance protein is absent in the infected plant cells. Using Affymetrix Arabidopsis DNA chip, we found that many genes were specifically regulated by AvrRpt2 protein in the rps2 Arabidopsis mutant. Here, we showed that expression of AtERF11 that is known as a member of B1a subcluster of AP2/ERF transcription factor family was down regulated specifically by AvrRpt2. To determine its function in plant resistance, we also generated the Arabidopsis thaliana transgenic plants constitutively overexpressing AtERF11 under CaMV 355 promoter, which conferred an enhanced resistance against a bacterial pathogen, Pseudomonas syringae pv. tomato DC3000. Thus, these results collectively suggest that AtERF11 plays a role as a positive regulator for disease resistance against biotrophic bacterial pathogen in plant.

• Journal of Oral Medicine and Pain
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• v.42 no.1
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• pp.1-7
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• 2017

Purpose: The aims of this study were to evaluate the clinical characteristics and polysomnographic results of patients visited the Seoul National University Dental Hospital (SNUDH) and to suggest guidelines for the management of sleep disordered-breathing patients in a dental clinic. Methods: Five hundred sixty-two patients who visited the Snoring and Sleep Apnea Clinic of SNUDH were evaluated for clinical characteristics including associated comorbidities, age, gender, body mass index (BMI), neck circumference, and daytime sleepiness and among them 217 patients were performed nocturnal polysomnography for evaluating respiratory disturbance index, apnea-hypopnea index (AHI), oxygen saturation levels, and sleep stages. The associations among clinical characteristics, sleep parameters, and positional and rapid eye movement (REM) dependencies of the patients were analyzed. Results: The most common co-morbidities of the patients were cardiovascular (30.2%), endocrine (10.8%), and respiratory diseases (7.9%). Age (${\beta}=0.394$), total AHI (${\beta}=0.223$), and lowest $O_2$ saturation levels (${\beta}=0.205$) were significantly associated with the number of co-morbidities in patients with obstructive sleep apnea (OSA). Mean $O_2$ saturation was not significantly associated with number of co-morbidities. Non-positional OSA patients had higher BMI, longer neck circumferences, more severe AHI values, and lower mean and lowest $O_2$ saturation levels compared to positional OSA patients. Not-REM-related patients were older and had more severe AHI values compared to REM-related patients. Not-REM-related patients have longer duration of stage I sleep and shorter stage II, III, and REM sleep than REM-related patients. There were no significant differences in each sleep stage between positional and non-positional patients. Neck circumference, positional dependency, REM dependency, and percentage of supine position were significantly associated with severity of OSA. Conclusions: Age, total AHI, and lowest $O_2$ saturation level were significantly associated with the number of co-morbidities in patients with OSA. Neck circumference, positional dependency, REM dependency, and percentage of supine position were significantly associated with severity of OSA.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.673-682
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• 2006

Recent study shows that implant design has a great impact on initial stability in bone. The ITI $TE^{(R)}$ implant, designed originally for immediate placement has a tapered/ cylindrical form which fits the anatomical shape of the natural alvelous or tooth root. The increased diameter at the collar region coupled with more threads lead to more bone contact and enhanced stability. The aim of this retrospective study is to evaluate the clinical use and the efficacy of recently introduced ITI TE implant with a new macro-design. The following results are compiled from 139 patients who received ITl TE implant surgery at the periodontal department. of Yonsei University Hospital between July 2002 and September 2005. 1. 139 patients received 173 ITl $TE^{(R)}$ implants in their maxilla and mandible (Mx 82, Mn 91). Posterior area accounted for 84% of the whole implant surgery, 2. In the distribution of bone quality, type III(41,0%) was the most, followed by type IV(41,0%) and type II (27.7%). As for the bone quantity, type B(43.9%) was the most, followed by type C(42.2%), type D(12.2%) and type A(1.7%). 3. 125 implants(83.9%) were treated by single crown, which accounted for the majority. 4, The total implant survival rate was 100% after a mean follow-up period of 21.2 months. This preliminary data with ITl $TE^{(R)}$ implant showed excellent survival rate although the majority of implants evaluated in this study were placed in the posterior region of the jaw and compromised sites.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.136-143
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• 2004

The purpose of this study was to investigate the relationship between morphology and position of deciduous double teeth, and the occurrence of other dental anomalies in the same subject. Four morphological types were indentified according to Ailing's classification: type I, bifid crown-single root; type II, large crown-large root; type III, two fused crowns-single root; type IV, two fused crowns-two fused roots. Fifty-four double teeth were found in a total of 1,803 children, who had visited Wonkwang university hospital for dental treatment from January 1, 2003 to September 30, 2003. All of these children were examined clinically and intra-oral radiographs were taken. The results were as follows; 1. 49 children(2.7%) had more than one double teeth, 5 of these children had two double teeth on the bilateral side. And one child showed triple teeth which has three crowns and three roots. 2. Double teeth were predominantly situated in the anterior region, with a preference for the mandible. The ratio of cases involving central incisor and lateral incisor was higher than other cases. 3. There were 25 cases(46.2%) of missing successors among 54 cases of the double teeth. And, prevalence of the missing teeth was highest in the cases involving maxillary central incisor and lateral incisor. 4. In the case of type II(large crown-large root) had more missing successors.