• Journal of dental hygiene science
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• v.9 no.3
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• pp.353-360
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• 2009

The purpose of this study was to investigate the recognition for improvement of the Korean Dental Hygienists' Licensing Examination(KDHLE). The subjects were 1,048 dental hygienists were surveyed. either in person or through mail. Data was collected using a self administrated questionnaire from July 1 to July 20, 2008. The data were analysed with frequency and $x^2$-test using the SPSS 15.0 windows. For the inquiry where adequacy of subjects of the KDHLE regarding to evaluation of standard duty achievement ability in the real field was asked, 404(39.5%) answered 'Yes', and 680(66.9%) was answered 'Yes' for necessity of changing current subjects of the KDHLE. For the inquiry about the number of questions in the KDHLE, 353(34.6%) answered that current number of questions is 'Inappropriate' and advisable way of improving KDHLE subjects, 463 (45.4%) answered 'enhancing problem solving ability through unifying subjects', the highest of all. About practical examination methods, 647(67.3%) was answered 'Should be modified'. For methods of dental hygienist practical examination, 'clinical demonstration on patients' received the highest number of votes 628(63.6%). According to the above results, most of active dental hygienists at presence expect the alteration of current KDHLE and new items which are reliable for globalization by testing problem solving ability through unified subjects must be introduced.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.6
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• pp.253-257
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• 2008

To enhance the luminescence properties, the red phosphor composed of $(Y,\;Zn)_2O_3$:$Eu^{3+}$ as doping concentration of Zn ion is synthesized at $1200^{\circ}C$ for 6 hrs in air atmosphere by conventional solid reaction method. As a result of the red phosphor $(Y,\;Zn)_2O_3$:$Eu^{3+}$ is measured X-ray diffraction (XRD), The main peak is nearly corresponded to the same as JCPDS card (No. 41-1105). When the doping concentration of Zn ion is more than 5 mol%, However, the ZnO peak is showed by XRD analysis. Therefore, when the doping concentration of Zn ion is less than 5 mol%, the Zn ion is well mixed in $Y_2O_3$ structure without the impurity phases. The photoluminescence (PL) properties is shown as this phosphor is excited in 254 nm region and the highest emission spectra of $(Y,\;Zn)_2O_3$:$Eu^{3+}$ has shown in 612 nm region because of a typical energy transition ($^5D_0{\rightarrow}^7F_2$) of $Eu^{3+}$ ion. As the doping concentration of Zn ion is more than 10 mol%, the emission peak is suddenly decreased. when the highest emission peak as doping concentration of Zn ion is shown, the composition of this phosphor is $(Y_{0.95},\;Zn_{0.05})_2O_3$:$Eu^{3+}_{0.075}$ and the particle size analyzed by FE-SEM is confirmed from 0.4 to $3{\mu}m$.

• Journal of the Mineralogical Society of Korea
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• v.6 no.2
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• pp.57-79
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• 1993

Chuncheon nephrite, which was formed by the polymetasomatic alteration of dolomitic marble, can be classified into pale green, green, dark green, and grey types on the basis of their occurrence, mineralogical and textural characteristics. The nephrites consist obiefly of fibrous or hairlike(length/width ratio>10) cryptocrystalline(crystal width < $2{\mu}m$) tremolite, and include less amounts of micro-crystalline diopside, calcite, clinochlore, and sphene as impurities. The oriented and rather curved crystal aggregate, of nephritic tremolite are densely interwoven, resulting in a massive-fibrous texture which may explain the characteristic toughness of nephritic jade. The characteristic greenish color of the nephrite may be preferably related to Fe rather than Cr and Ni. However, the variation of color and tint in the Chuncheon nephrite also depends on the mineralogical and textural differences such as crystallinity, texture, and impurities. The chemical composition of the nephritic tremolite is not stoichiometric and rather dispersed especially in the abundances of Al, Mg, and Ca. Al content and Mg/Ca ratio for the nephritic tremolite are slightly increased with deepening in greenish color of the nephrite. Fe content in the nephritic tremolite is generally very low, but comparatively richer in the dark green nephrite. In nephritic tremolite, wide-chain pyriboles are irregularly intervened between normal double chains, forming a chain-width disorder. Most nephritic tremolites in the Chuncheon nephrite show various type of chain-width defects such as triple chain(jimthompsonite), quintuple chain (chesterite), or sometimes quadruple chain in HRTEM observations. The degree of chain-width disorder in the nephritic tremolite tends to increase with deepening in greenish color. Triple chain is the most common type, and quadruple chain is rarely observed only in the grey nephrite. The presence of pyribole structure in the nephritic tremolite is closely related to the increase of Al content and Mg/Ca ratio, a rather dispersive chemical composition, a decrease of relative intensity in (001) XRD reflection, and an increase in b axis dimension of unit cell. In addition, the degree and variation of chain-width disorder with nephrite types may support that an increase of metastability was formed by a rapid diffusion of Mg-rich fluid during the nephrite formation.

• Korean Journal of Veterinary Research
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• v.5 no.1
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• pp.1-16
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• 1965

I. A Comparison of Sodium Sulfate Precipitation and Zone(Paper, Agar) Electrophoresis; Many kinds of techniques have been used for fractionating serum proteins. In the present study, using bovine serum, the fractions obtained with sodium sulfate were compared with those determined by zone electrophoresis. 1. Fibrinogen was precipitated with 4 to 10 percent of sodium sulfate. 2. ${\gamma}$-globulin required 10 to 16 percent of the salt for precipitation. 3. ${\beta}$-globulin began to precipitate at 12 percent sodium sulfate, and completed precipitation at approximately 26 percent in paper electrophoresis, while at 22 percent in agar electrophoresis. 4. ${\alpha}$-globulin completed precipitation at 13 to 28 percent sodium sulfate in paper electrophoresis and at 22 percent in agar electrophoresis. 5. Albumin began to precipitate at 14 percent of the salt, and was free from the mixture of globulins approximately at 28 percent in paper electrophoresis, while at 22 percent in agar electrophoresis. The results of comparing fractions by the two methods were as follows: 1. Euglobulin (15%) was equal to the sum of the most ${\gamma}$-globulin and a small quantity of the ${\alpha}$-, and ${\beta}$-globulins. 2. Pseudoglobulin I (15-17.5%) corresponded to the most ${\alpha}$-, ${\beta}$-globulins and a small quantity of albumin. 3. Pseudoglobulin II(18-22%) was a mixture of the ${\alpha}$-, ${\beta}$-globulins and albumin fraction. 4. Albumin (above 22%) contained the most albumin fraction separated by zone electrophoresis and a small quantity of the ${\alpha}$-, and ${\beta}$-globulins. As mentioned above the fractions obtained with sodium sulfate were a mixture of the various proportion of the fractions determined by zone electrophoresis. The solubility of serum fractions to sodium sulfate coincided with the mobility of those by zone electrophoresis. (By percent of sodium sulfate we mean gram of sodium sulfate contained in $100m{\ell}$ of solution). II. Immunological Studies on Serum Protein Fractions with Sodium Sulfate; In the previous report the fractions of bovine serum protein with sodium sulfate compared with those obtained by zone electrophoresis, and the findings were that the former contained various proportion components of the latter. In this study the author studied whether or not the fractions with sodium sulfate are simple component antigenically by immunoelectrophoresis and micro double diffusion test (Immuno-precipitation), using rabbit antiserum to bovine serum. In immunoelectrophoresis, normal bovine serum developed with rabbit antibovine serum showed about ten distinct precipitin arcs. The distribution of these arcs was as follows: 1 albumin, 2 ${\alpha}_1$-, 3 ${\alpha}_2$-, 2 ${\beta}_1$-, ${\beta}_2$-, and 1 ${\gamma}$-globulin (Fig. 7, 9). In micro double diffusion test, five to six precipitation bands could be seen between antigens and antibody, the order of the precipitation bands location is albumin, ${\alpha}$-, ${\beta}$-, and ${\gamma}$-globulin from the side of antiserum well (Fig.19). Frequently the ${\alpha}$-, and ${\beta}$-precipitation bands were separated into two or three precipitation bands, which indicated that these globuline are not a pure component antigenically as shown in immuno-electrophoresis. In both Immunological methods, the two ${\alpha}$-, ${\beta}$-precipitin arcs and bands appeared clear and strong, indicating that the two globulins reacted as strong antigens. The precipitate reaction of ${\gamma}$-globulin was shown at 12 to 16 percent sodium sulfate; ${\beta}$-globulin at 12 to 20 percent; ${\alpha}$-globulin at 12 to 22 percent (immuno-electrophoresis), at 12 to 26 percent (Diffusion); and albumin at above 22 percent. Antigenically euglobulin contained ${\gamma}$-, ${\beta}$-, and ${\alpha}$-globulins, Pseudoglobulin I and Pseudoglobulin II were composed of ${\alpha}$-, and ${\beta}$-globulins, and albumin was a mixture of ${\alpha}$-globulin and albumin determined by zone electrophoresis. The results indicated that the fractions of serum protein obtained by either method were constituents of various proteins antigenically except ${\gamma}$-globulin and albumin by Zone electrophoresis.

• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.421-430
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• 1997

Alveolar bone grows with development of tooth germs and roots; bone deposition occurs with tooth eruption. Bone components undergoes processes of resorption and deposition, and when the balance between them is disrupted, decrease in alveolar bone height or excessive bone deposition result. It has been hon that repositioning of teeth through orthodontic treatment can cause alveolar bone resorption which result in decreased alveolar bone height, and there have been many studies to evaluate such effects. X-ray films that could be replicated and standardized were chosen in clinical studies, and among them, bitewing films were used for objective evaluation of changes in alveolar bone level. Twenty subjects, 10 to 13-year- old (average 12.2) children with Cl I molar key, healthy oral condition, no congenital missing, no periodontal disease, and pre-and post-orthodontic bitewing films, were randomly selected for comparison of alveolar bone heights. Amounts of tooth and changes in alveolar bone heights were analyzed. The following results were obtained: 1. Amount of tooth movement in canine, premolar, and molar regions, changes in tooth axis, and changes in alveolar bone heights were measured, and the mean and median values were obtained. 2. When pre-and post-orthodontic alveolar bone levels were compared, larger changes were noticed in maxilla than mandible. 3. When mesio-distally compared, larger changes were observed in the distal sides of 3D3 and 4M3, mesial sides of 4M3 and 4D3, distal sides of 4D3 and 5M3, mesial sides of 5M3 and 5D3, md distal sides of 5D3 and 6M3. 4. When the amounts of tooth movements(TX, TY)and changes in tooth axis(A) were compared,34TX, 34TY, 34A of both sides in maxilla were greater, iud changes in alveolar bone level were greater than any other region.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.185-189
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• 2004

The purpose of this study was to determine the possibility of in vitro maturation of tiger oocytes. Immature oocytes were recovered from a pair of ovaries. A total of 78 oocytes was collected, of which forty three were classified as good oocytes with compact cumulus cells and uniform cytoplasm. Forty three COCs were in vitro matured at $39^{\circ}C$, 5% CO2 in air atmosphere for 48 h in a IVM medium (TCM-199 supplement with 10% FBS, 0.6 mM cysteine, 0.2 mM pyruvic acid and 10 IU/mL HMG). Experiment I: the morphologic evaluation was conducted by measuring the diameter of oocytes with or without ZP, the thickness of ZP and the diameter of cytoplasm by microeyepiece at the same magnification (${\times}$100). Experiment II: the evaluation of meiotic development was conducted of the nuclear development stage of tiger oocytes. The results were summarized as follows: 1. The diameter of tiger oocytes $(176.5\pm6.1{\mu}m)$ with ZP was significantly (p<0.05) bigger than that of bovine oocytes $(150.7\pm4.9{\mu}m).$ The ZP thickness of tiger oocytes $(20.4\pm2.9{\mu}m)$ was significantly (p<0.05) bigger than that of bovine oocytes $(12.0\pm2.6{\mu}m;$ p<0.05). However, there was no significant difference in the diameter of cytoplasm (without ZP) between tiger $(122.1\pm9.7{\mu}m)$ and bovine oocytes $(118.7\pm7.5{\mu}m).$ 2. The rates of meiotic development of tiger oocytes were achieved GV (12.5 %) and MII (50.0%), respectively. These results indicated that tiger oocytes could be developed to MII in in vitro culture system.

• Sleep Medicine and Psychophysiology
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• v.15 no.2
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• pp.87-93
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• 2008

Introduction: Although it is well known that medical students are not getting an adequate amount of sleep, there have been only few studies on the sleep patterns of medical students in Korea. Therefore, the present study aimed to investigate the life style and sleep patterns of Korean medical students and the impact they have on the students' academic performance. Methods: A questionnaire package was administered to the $3^{rd}$ year medical students at the Seoul National University to examine their sleep patterns on weekdays and weekends. It consisted of questions asking about their lifestyles as well as Pittsburgh sleep quality index (PSQI) and GPA (Grade Point Average) that are considered relevant to their sleep patterns. A total of 110 students (85 males and 25 females, mean age $24.4{\pm}20.6$) responded to the survey and the result was analyzed using the independent t-test, the chi-square test, the paired t-test, Pearson's rank correlation and ANOVA. P-values of less than 0.05 were considered statistically significant in all analyses. Results: The weekend bedtime was significantly delayed (01：24 on weekday；03：12 on weekend; t=-5.23, p<0.01), the weekend rise time was delayed (07：36 on weekday；10：30 on weekend ; t=-24.48, p<0.01) and the total sleep time was increased on weekends (5：57 on weekday；8：17 on weekend ; t=15.94, p<0.01). They wished to sleep for 7 hours 6 minutes which was different from their actual weekday total sleep time (t=-11.41, p<0.01). The poor sleeper group had lower GPAs than the good sleeper group (t=2.05, p<0.05). The GPA of medical students were negatively correlated with age (r=-0.23, p<0.05), daily amount of smoking (r=-0.78, p<0.01), total amount of smoking (r=-0.75, p<0.01), weekday sleep latency (r=-0.23, p<0.05), weekend sleep latency (r=-0.23, p<0.05) and PSQI score (r=-0.30, p<0.01). Conclusion: Medical students were experiencing a lack of sleep during weekdays as they have a later bedtime and earlier rise time, and consequently had more hours of sleep on weekends. Overall, the responded students were experiencing poor sleep quality, and the GPAs of the poor sleeper group were lower than those of the good sleeper group.

• Health Policy and Management
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• v.14 no.1
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• pp.65-88
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• 2004

In general, empowerment is defined as the motivational concept of autonomy and self-efficacy. Recently, the concept of empowerment is applied to improve organizational staff's job satisfaction and organizational commitment in many organizations. Empower-ment in service organizations, i.e., hospitals, has certainly generated more publicity than any other organizations. The objectives of this study are, first, to measure the degree of hospital employees' empowerment using Spreitzer(1995)'s empowerment theory, second, to analyze the causal relationship of organizational and job characteristics, a degree of empowerment, and organizational performance(job satisfaction and organizational commitment), and third, to offer the strategy for the improvement of job satisfaction and organizational commitment. Spreitzer insists that the empowerment is composed of 4 dimensions(meaning, competence, self-determination, and impact). And he argues that various work-related characteristics is a direct cause of empowerment and the indirect cause of job satisfaction and organizational commitment, mediated by the empowerment latent variable. In order to perform this study, data were collected by self-administered questionnaires from hospital employees working in administrative department of 3 university hospitals in Inchon and Kyunggi-Do region. The number of cases is 181(response rate; 86%). The Collected data were analyzed with SPSS Ver. 10.0 and AMOSV Ver. 4.0. First, to test validity of variables, the factor analysis was used. Second, to test reliability, Cronbach's alpha coefficients was calculated. Cronbach's alpha of empowerment variable is 0.8323 showing that there's no problem in regard to the internal consistency. Also the Cronbach's alpha of other variables are 0.8301 of the degree of perceived control, 0.6705 of job characteristics, O.8787 of compensation, 0.9254 of job satisfaction, and 0.8389 of organizational commitment, respectively. Among the questions of job characteristics, two survey questions are deleted due to lowering the reliability. Third, to test multicollinearity and correlation of variables, the correlation analysis was performed. There was no problem of multicollinearity. Finally structural equation modelling (SEM) analysis was conducted to find the causal relationship of organizational and job Characteristics, empowerment, job satisfaction and organizational commitment. The 16 variables are included for the SEM analysis. The major results of this study are as follows: First, in the case of model fitness, the condition of x$^2$ statistic(92.187) is not fully satisfied, but the indices of GFI(0.912), AGFI(0.863), NFI(0.917) and CFI(0.928) are partially satisfied, which needs to upper 0.90. Second, in the result of hypotheses testing, all hypotheses are accepted and have a positive effect in 95% or 99% confidence interval(P<0.05 or P<0.001) except the effect of compensation variable on empowerment(P=0.082). Third, in regard to the direct, indirect, and total effect of variables, the direct effect of perceived control, task characteristics, and compensation on job satisfaction are 0.728, 2.264, 0.328 and on organizational commitment are 0.094, 1.411, 0.418, respectively. Also the indirect effect of perceived control, task characteristics, and compensation on job satisfaction are 0.311, 0.196, 0.028 and on organizational commitment are 0.210, 0.132, 0.019, respectively. Thus, these findings imply that various work-related factors are direct effect of empowerment and indirect effect of result variables, job satisfaction and organizational commitment. Also These results showed that the workplace empowerment is significant mediating factor of employee's job satisfaction and organizational commitment.

• Progress in Medical Physics
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• v.17 no.3
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• pp.173-178
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• 2006

The purpose of this study was to evaluate the radiation dose for clinical PET/CT protocols in clinical environments using Alderson phantom and TLDs. Radiation doses were evaluated for both Philips GEMINI 16 slice PET/CT system and GE DSTe 16 slice PET/CT system. Specific organ doses with $^{137}Cs$ transmission scan, high quality CT scan and topogram in philips GEMINI PET/CT system were measured. Specific organ doses with CT scan for attenuation map, CT scan for diagnosis and topogram in GE DSTe PET/CT system were also measured. The organs were selected based on ICRP60 recommendation. The TLDs used for measurements were selected for within an accuracy of ${\pm}5%$ and calibrated in 10 MV X-ray radiation field. The effective doses for $^{137}Cs$ transmission scan, high qualify scan, and topogram in Philips GEMINI PET/CT system were $0.14{\pm}0.950,\;29.49{\pm}1.508\;and\;0.72{\pm}0.032mSv$ respectively. The effective doses for CT scan to make attenuation map, CT scan to diagnose and topogram in GE DSTe PET/CT system were $20.06{\pm}1.003,\;24.83{\pm}0.805\;and\;0.27{\pm}0.008mSv$ respectively. We evaluated the total effective dose by adding effective dose for PET Image. The total PET/CT doses for Philips GEMINI PET/CT (Topogram+$^{137}Cs$ transmission scan+PET, Topogram+high qualify CT+PET) and GE DSTe PET/CT (Topogram +CT for attenuation map+ PET, Topogram+diagnostic CT+ PET) are $7.65{\pm}0.951,\;37.00{\pm}1.508,\;27.12{\pm}1.003\;and\;31.89{\pm}0.805mSv$ respectively. Further study may be needed to be peformed to find optimal PET/CT acquisition protocols for reducing the patient exposure with good image qualify.

• Tuberculosis and Respiratory Diseases
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• v.58 no.3
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• pp.257-266
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• 2005

Background : The study of pneumonia among young men living in a group is rare. prospective study was conducted to determine the etiology, and compare the effects of macrolide and second-generation cephalosporin on the treatment of pneumonia among combat policemen. Patients and Methods : From January 2003 to April 2004, Fifty-two patients with pneumonia were treated with either azithromycin(n=25) or cefuroxime(n=27). In order to determine the cause of the pneumonia, culture studies and serologic tests for antibodies to Mycoplasma pneumoniae and Chlamydia pneumoniae were carried out. During the two weeks of medication, the Chest X-rays, blood tests and culture studies(if necessary) were followed weekly. A serologic study was followed at the end of the second week. Results : The main pathogens for pneumonia among combat policemen were Mycoplasma pneumoniae(50.0%), Chlamydia pneumoniae(10.8%), and Streptococcus pneumoniae(3.8%). The treatment was successful in most cases(51/52 cases, 98.1%). The effects of azithromycin and cefuroxime were similar (96.0% vs 100%, p>0.05). In one patient who had taken azithromycin, the clinical and radiological findings did not improved until intravenous second generation ce phalosporin had been infused. Conclusion : Atypical pathogens were the main causes of the pneumonia in the combat policemen, and the effects of macrolide and second generation cephalosporin for pneumonia were similar. However, further studies will be needed to determine if single therapy with macrolide is possible.