• The Journal of Korean Academy of Prosthodontics
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• v.44 no.2
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• pp.165-173
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• 2006

Purpose: With gold electroforming system fir the double crown, the secondary crown is electroformed directly onto the primary crown. An even thick layer of high precision can be acquired. It is thought that the retention of electroformed outer crown is primarily acquired by the adhesive force (surface tension) through the saliva which is interposed between precisely fitted inner and outer crown. The purpose of this study was to investigate the effect of taper and surface area of inner crown on the retentive force of electroformed outer crown according to the presence of saliva. Materials and methods: 32 titanium inner crowns with cervical diameter of 8 mm and cone angles of 0, 2, 4, 6 degrees, which had same surface area by regulated height, were machined on a lathe. Another 32 titanium inner crowns with cone angles of 0, 2, 4, 6 degrees, which had doubled surface area by increased cervical diameter. were fabricated. Eight specimens of each group, for a total of 64 titanium inner crowns, were prepared. The electroformed outer crowns were fabricated directly on the inner crowns by using electroforming machine(GAMMAT free, Gramm Technik, Germany). The tertiary frameworks were waxed-up on the electroformed outer crown and cast using nonprecious alloy($Rexillium^(R)III,\;Jeneric^(R)/Pentronh^(R)$ Inc., USA). The cast metal frameworks were sandblasted with alubimium oxides and cemented using resin cement(Superbond C&B, Sun Medical Co., Japan) over the electroformed copings of each specimen. Then, artificial saliva($Taliva^(R)$, Halim Pharm. Co., Korea) was sprayed between the inner and outer crown, and they were connected under 5 kg force. The retentive force was measured by the universal testing machine(Tinius Olsen 1000, Tinius Olsen, USA) with a cross-head speed of 66.67 mm/sec. The direction of cross-head travel was exactly aligned with the path of removal of the respective specimens. This measurement procedures for retentive force of electroformed outer crown with artificial saliva were repeated in the same way without presence of artificial saliva. Results and Conclusion: The following conclusions were drawn: 1. The retentive force of electroformed outer crown was decreased according to increased taper of inner crown(P<.05). 2. The retentive force of electroformed outer crown showed no significant differences according to surface area and the presence of artificial saliva(P>.05).

• The Journal of the Acoustical Society of Korea
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• v.34 no.4
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• pp.274-281
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• 2015

Although noise-induced hearing loss (NIHL) is a significant public health problem, many people might not be aware that exposure to loud noise could occur hearing loss. The purpose of this study is to evaluate and analyze how importantly and seriously people are aware of NIHL using a 22-question survey. It was administered to random 150 people including between 20 s to 60 s. The questionnaire contained questions about i) views toward general health issues including hearing loss and tinnitus, ii) noise exposure, and iii) views toward hearing protection. Results showed that hearing loss was defined on a likert scale as 'a very big problem' by 17.33 % of respondents compared with other health issues. Surprisingly, most respondents (82 %) had not heard, read, or seen anything lately related to the issue of hearing loss. Many respondents had experience hearing problem or tinnitus under loud noise situations (85 %), however, only 11.33 % of respondents had used earplugs. Fortunately, many could be motivated to try ear protection if they were advised by a medical professional (80 %) or were aware of the potential for permeant hearing loss (78.67 %). We concluded that awareness of the potential for permanent hearing loss with noise and effective methods of hearing protection should be announced to public for preventing NIHL.

• Journal of the Korean Chemical Society
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• v.37 no.7
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• pp.655-661
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• 1993

The neutral monomeric compounds $[Mo(NO)_2Cl_2(phen)]$ and $[W(NO)_2Cl_2(phen)]$ (phen= 1,10-phenanthroline) have been prepared by reactions of polymeric compounds $[{Mo(NO)_2Cl_2}n],\;[{W(NO)_2Cl_2}n]$ with chelate ligands. Additions of one equivalent of silver(I) perchlorate to these cis-dinitrosyl compounds in acetone solution produce $[Mo(NO)_2(phen)(S)Cl][ClO_4]\;and\;[W(NO)_2(phen)(S)Cl][ClO_4]$ (S = acetone). The homo- and hetero-dinuclear complexes, $[Cl(phen)(NO)_2M(pyz)M'(NO)_2(phen)Cl][ClO_4]_2$ (M = Mo, W) and $[Cl(phen)(NO)_2M(pyz)M'(NO)_2(phen)Cl][C1O_4]_2$ (M = Mo, M' = W) have been prepared by these monocationic complexes with pyrazine ligand respectively. These complexes characterized by elemental analysis, $1^H-\;and\;^{13}C-NMR$, infrared, and UV-visible spectroscopy are reported. The spectral data indicate that homo- and hetero-dinuclear complexes were symmetrical structures of $C_{2v}$.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.602-608
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• 2011

Purpose: Nasal bone fracture is the most common type of facial bone fracture and most of nasal bone fracture is combined with septal fracture frequently. Nasal septum is important to support the distal nose and to maintain the nasal airway. But nasal septal fractures are usually unrecognized and untreated at the time of operation. Recently, various materials were using for nasal packing after closed reduction, however these materials are not focused on the correction of nasal bone and nasal septal fracture and many patients are suffered from nasal packing materials. Thus, the purpose of this study is to compare routine packing materials and rolled silastic sheet with respect to postoperative effect of correction of nasal bone fracture and discomfort of nasal packing materials. Methods: We examined 320 patients treated nasal bone fracture from January 2008 to December 2010. For Group I (n=92), $Merocel^{(R)}$ was used for nasal packing, for Group II (n=152) vaseline gauze was used, and Rolled silastic sheet (RSS) with vaseline gauze packing (VGP) was used for Group III (n=76). Under the general anesthesia, all patients were operated by closed reduction and nasal packing was done using three kinds of packing materials. At the time of postoperative 7 days, packing material was removed and studied for pt's satisfaction and postop. complications. Results: In patients with RSS with VGP, the complaints (nasal obstruction, foreign compressive sensation and discomfort during food ingestion) of keeping the nasal packing were decreased ($p$ <0.05) and the postoperative complication (deviation) were decreased comparing to vaseline gauze packing and $Merocel^{(R)}$ packing, however, these differences were not statistically significant ($p$ >0.05). Conclusion: Postoperative nasal packing with RSS with VGP was more comfortable to the patients and it was more effective method to correct the nasal bone fracture and nasal septal fracture.

• Restorative Dentistry and Endodontics
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• v.30 no.6
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• pp.477-485
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• 2005

The aim of this study was to compare the length between the mesio-buccal and mesio-lingual canal of the mandibular molars before and after early coronal flaring at the different measuring time using several electronic apex locators. Fifty mandibular molars with complete apical formation and patent foramens were selected. After establishing the initial working length of the buccal and lingual canal of the mesial root using a surgical microscope (Carl Zeiss Co Germany) at 25X with #15 K-fle tip just visible at the foramen, radiographs were taken for the working length. After measuring the length of mesio-buccal and mesio-lingual canal (control group), the electronic lengths were measured at different times using several electronic apex locators (experimental groups; I-Root ZX, II-Bingo, III-Propex, IV-Diagnostic). After early coronal flaring using the $K^3$ file, the additional electronic lengths were measured using the same manner The results were as follows: One canal has a correct working length for the mesial root of the mandibular molar, it can be used effectively for measuring the electronic working length of another canal when the files are superimposed or encountered at the apex. In addition, the accuracy of the electronic apex locators was increased as the measurement was accomplished after the early coronal flaring of the root canal and the measuring time was repeated.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.2
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• pp.241-251
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• 1997

체외성숙과 수정된 돼지 난자의 체외발달능이 체외배발생 배양액인 NCSU 배양액에 0.4% BSA, 10% 혈청 혹은 아미노산 (2% BME 아미노산 용액과 1% MEM 아미노산 용액)을 첨가함으로서 조사되었다. 본 실험에 공시된 난자는 체외수정 추 30시간 (2-세포기)혹은 48 시간 ($2{\sim}4$-세포기)에 회수하였다. 실험I에서 0.4% BSA가 첨가된 NCSU 배양액에서 2-세포기 난자들의 배양경과시간에 따른 발달능을 조사한 결과, 배양 후 72 시간 (체외수정 후 102 시간)에 상실배기와 배반포기 배가 나타났으며, 배양 후 120 시간째 (체외수정 후 150 시간)에도 팽창된 배반포기 배까지만 발달하였다. 실험II는 체외수정 후 48 시간의 분할된 ($2{\sim}8$-세포기) 난자들의 핵과 외관적 분할구와의 수적 차이를 조사한 결과, $2{\sim}4$-세포기보다는 5-세포기 이상에서 핵과 분할구의 조화에 차이가 많았다. 실험III에서는 $2{\sim}4$-세포기 난자들을 배양후 5일째의 배반포들의 투명대의 두께, 난자 크기 그리고 inner cell mass (ICM)과 trophectoderm (TE)의 세포 배열을 조사한 결과, 난자의 크기가 커짐에 따라서 투명대가 얇아지고 전체 세포수가 증가하였지만, ICM의 비율은 차이가 없었다. 실험IV에서는 BSA, 혈청 혹은 아미노산이 첨가 혹은 무첨가된 배양액내에서 $2{\sim}4$-세포기 난자들의 배반포 후 부화능력을 조사한 결과, 모든 군에 있는 난자들은 팽창된 배반포기 배까지 발달할 수 있었던 반면, 난자의 부화는 아미노산 혹은 혈청이 포함된 배양액에서만 일어났다. 더우기 상실배기와 배반포기 시기에 혈청의 첨가는 부화 배반포기 배의 발달을 현저히 증가시켰다. 또한 아미노산과 혈청의 영향을 받은 팽창 배반포기 배는 얇은 투명대, 팽창된 난자의 크기 그리고 ICM과 전체 세포수의 증가를 보였다. 이상의 결과로 미루어 볼때, 배양액내에 대한 아미노산과 혈청의 첨가는 돼지 배반포기 배의 부화를 유도할 수 있다고 보며, 더우기 이들 요소들은 투명대의 두께, 난자의 크기 그리고 ICM과 전체 세포수에 영향을 미친다.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.4
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• pp.228-236
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• 2008

Purpose: The purposes of this study is to provide basic informations on oriental medical research and treatment through analysis of breast cancer patients, who visited M $\mu$ integrative cancer center, O O university East-West neo medical center. Methods: Electronic medical records of 106 breast cancer patients who visited oriental medical center from June 2, 2006 to February 28, 2008 were selected to collect clinical data of those patients. Clinical data were analyzed for types of clinical characteristics, and received therapies. For analysis of survival and recurrence, Kaplan-Meier method was used. All the data were processed and analyzed using SPSS version 13.0. Results: Average age of breast cancer patients, who visited oriental medical center was 48.72 ($\pm$10.13). The stage distribution record indicated stage I (5.8%), stage II (7.0%), stage III (5.8%), and stage IV (81.4%). Original purposes of patients were analyzed to be supplementary treatment for western therapy (68.9%), treatment for recurrence prevention (18.9%), and oriental medical treatment (12.2%) in order. While receiving oriental medical treatment, 60.4% of patients received conventional medical treatment simultaneously. Conclusion: Majority of patients who visited oriental medical hospital were stage IV at terminal stage and mainly visited for the purpose of supportive care. Further clinical study of breast cancer patients is needed to validate the effectiveness of oriental medical treatment based on this study.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.25 no.4
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• pp.45-56
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• 2012

Objective : This study was done to investigate the correlation between general quality of life(QOL) and disease specific QOL of tinnitus patients. Methods : 2009 National health and nutrition survey(NHNS) data were employed for analyzing the mean estimates of total population and tinnitus sub-group patients, and predicting the regression equation of mapping between EQ-5D and disease severity. Baseline statistical analyses and normality tests were done by using Student t-test, Chi-square test, Shapiro-Wilk test and ladder test. Hierarchial regression analyses were performed using related variables and predicted the optimal regression equations. Statistical significance was achieved if the probability was less than 5%. Results : Firstly, the standardized prevalence of tinnitus patient in South Korea was 18.69% and over 90th age-group was relatively higher than other groups. Mean value of domestic QOL measured by EQ-5D was estimated as 0.9486 and QOL of tinnitus subgroup(0.9169) was lower than the non-tinnitus subgroup(0.9559), significantly. Stratified by age and sex, QOLs of all sub-groups with tinnitus were lower than without tinnitus sub-groups significantly. Regression equations from 2009 NHNS data were developed using hierarchial regression analysis which is as follows. $$Y_{EQ-5D}=0.9224-0.0079{\times}T1-0.0261{\times}T2-0.0951{\times}T3+\sum_{i=1}^{n}{\beta}_i{\times}X_i\\{\hspace{95}}(0.0106){\hspace{3}}(0.0037){\hspace{30}}(0.0072){\hspace{30}}(0.0038)$$ ($X_i$=Other explanatory variables except Tinnitus QOL1, 2, 3, ${\beta}$= Regression Coefficient of Model 4) Conclusion : We confirmed the correlation among THI and EQ-5D and HUI-III, and developed the inference for regression equation of EQ-5D.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.444-450
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• 2009

Amplified fragment length polymorphism (AFLP) marker was utilized for evaluation of genetic diversity of 60 pear germplasms. Twenty selective AFLP primer pairs generated a total of 522 polymorphic amplification products. From UPGMA (unweighted pair-group method arithmetic average) cluster analysis by using polymorphic bands, the pear germplasms were divided into four clusters by similarity index of 0.691. The first cluster (I) included European pears belonging to Pyrus communis and wild species such as P. nivalis and P. cordata. The second cluster (II) included Ussurian pea pears belonging to P. betulaefolia and P. fauriei. The third cluster (III) included pea pears belonging to P. calleryana and P. koehnei. Most of germplasms belonging to P. pyrifolia and P. ussuriensis, and interspecific hybrids were included in the fourth (IV) cluster. Therefore pear germplasms originated from East Asia were closely related to P. pyrifolia and P. ussuriensis. Similarity values among the tested pear germplasms ranged from 0.584 to 0.879, and the average similarity value was 0.686.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1057-1072
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• 2018

In this study, micro-sized $CeO_2$ particles were synthesized by spray pyrolysis, and EG(ethylene glycol) and CA(citric acid) as organic additives were added to obtain hollow and porous particle during spray pyrolysis, and characteristics of obtained ceria were investigated according to the amount of added organic additives. Spray pyrolysis, postheat and ball-milling were combined to give 6 paths. $CeO_2$ nano-sized particle was obtained by the path which has sequence of Spray Pyrolysis with 0.5 M of EG and CA${\rightarrow}$Post-heat${\rightarrow}$Ball-milling${\rightarrow}$Post-heat among 6 paths. The average particle size(24 nm with standard deviation of 3.8 nm) of $CeO_2$ nano-sized particle by TEM analysis is close to the primary particle size(20 nm) which was calculated by Debye-Scherrer equation. To investigate the morphological characteristics and structure of the synthesized nanoparticle powders, SEM(Scanning Electron Microscopy), XRD(X-Ray Diffractometer) and TEM(Transmission Electron Microscopy) were used.