• Journal of Preventive Medicine and Public Health
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• v.27 no.3 s.47
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• pp.517-530
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• 1994

For the purpose of providing the basic data for health management of workers who are exposed to chromium and for improving the quality of working environment, the authors evaluated blood and urinary level of chromium, the occupational history. AST, ALT, Hb, Hct, nasal specular examinaton on 287 workers who have been dealed chromium compounds in 56 manufacturing Industries of five types, that is, 38 metal plating services(plating),4 manufacture of other fabricated metal products (fabricated metal product), 5 manufacturing of dyestuff(dyestuff), 6 dressing and dyeing of leather(leather), 3 others(manufacture of pottery and ceramic househod wares, motor vehicles, electronic valves and tubes and other electronic components) and also measured the level of chromium in air from February to October 1993. The results were as follows ; 1. The utilized type of chromium compounds was the hexavalent state in plating fabricated metal product dyestuff, leather and the trivalent state in .other, and atmosperic chromium concentration as geometric mean was $0.0138mg/m^3(0.001{\sim}0.068mg/m^3)$ in plating, $0.0115mg/m^3(0.006{\sim}0.015mg/m^3)$ in fabricated matal product, $0.068mg/m^3(0.002{\sim}0.019mg/m^3)$ in dyestuff, $0.0083mg/m^3(0.002{\sim}0.028mg/m^3)$ in leather $0.0039mg/m^3(0.003{\sim}0.005mg/m^3)$ in other by the type of industry and it exceeded TLV-TWA ($0.05mg/m^3$) in five (13.6%) of plating services. 2. The geometric mean of chromium in blood was $1.54{\mu}g/dl(0.10{\sim}3.62{\mu}g/dl)$ in Plantng, $0.94{\mu}g/dl(0.27{\sim}2.82{\mu}g/dl)$ in fabricated metal product, $0.51{\mu}g/dl(0.10{\sim}3.25{\mu}g/dl)$ in dyestuff, $0.87{\mu}g/dl(0.15{\sim}8.00{\mu}g/dl)$ in leather, $0.55{\mu}g/dl(0.20{\sim}2.28{\mu}g/dl)$ in other by the type of industry(p<0.001). 3. The geometric mean of chromium in urine was $14.47{\mu}g/l(6.90{\sim}28.00{\mu}g/l)$ in planting, $4.63{\mu}g/l(0.24{\sim}43.00{\mu}g/l)$ in fabricated metal product, $5.93{\mu}g/l(1.00{\sim}33.00{\mu}g/l)$ in dyestuff, $11.09{\mu}g/l(0.80{\sim}48.00{\mu}g/l)$ in leather, $12.41{\mu}g/l(10.10{\sim}41.00{\mu}g/l)$ in other by the type of industry(p<0.001). 4. As the result of nasal specular examination, twenty four cases (8.4%) of nasal septal perforation among 287 total subjects was observed, and there were 17 (9.7%) cases in plating, 4 csaes (14.3%) in dressing and dyeing of leather. In the comparison of chromium concentration in blood and urine between the perforated group and non-perforated group, the perforated group showed a significantly higher value as $1.883{\pm}3.055{\mu}g/dl\;and\;0.793{\pm}0.815{\mu}g/dl$(P<0.001), $21.31{\pm}34.610{\mu}g/L\;and\;9.304{\pm}11.079{\mu}g/L$ (P<0.001). 5. The mean concentration of chromium in blood, urine and the mean level of AST, ALT, Hb and Hct in exposure group were higher than those of control group(p<0.001).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.8 s.99
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• pp.815-824
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• 2005

In this paper, we proposed a new DGS(Defected Ground Structure) Doherty amplifier for IMT-2000 band. Originally, active load-pull analysis of a Doherty amplifier assumes ideal harmonic termination condition. However, there have been no papers considering this ideal harmonic termination condition. We obtained excellent improvements of efficiency, gain, maximum output power as well as superior size reduction of a Doherly amplifier by satisfying the overlooked assumption of ideal harmonic termination through the adaptation of DGS at the output transmission line of carrier and peaking amplifier that is essential for Doherty operation. The amount of both the 2nd and the 3rd harmonic rejection of the proposed DGS Doherty amplifier over the conventional one are 44.92 dB and over 23.77 dB, respectively. The acquired improvement in Pl dB, gain, drain efficiency, and ACPR to WCDMA 1FA signal were 0.42 dB, 0.33 dB, $6.4\%$ and 5.4 dBc, respectively. Moreover, electrical length of $90{\circ}$ is reduced at each of the DGS carrier amplifier path and DGS peaking amplifier path, therefore the whole amplifier circuit size is considerably reduced.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.198-206
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• 2014

The purpose of this study was to develop and validate tool for measuring the communication skills of dental hygienist. The survey was modified and revised to fit into Korean culture. Also the reliability and validity was tested in order to ensure the survey was properly evaluating communication skills of dental hygienists. A survey was conducted with outpatients in dental clinics located in Seoul, Gyeonggi, and Daejeon area. The 483 answers out of the total collected answers were used for the final analysis of the study, using PASW Statistics 18.0 and IBM SPSS AMOS 7.0 to measure the validity and reliability. The factor analysis showed that the communication skill of the dental hygienists was composed of three elements, namely 'being caring and respectful' communications, 'sharing information' communications and 'tending to comfort' communications to reduce pain and anxiety. The validity of the model examined by a confirmatory factor analysis satisfied most of the relevant requirements. All of the factors had the conceptual reliability and variant extracted index above the minimum requirements, ensuring reliability and concentrated validity. Also, the value of the square of the correlations between all latent factors which was larger than the square of the correlation between all of the factors, thus proving the discriment validity. Cronbach's ${\alpha}$ was 0.8, which shows high reliability level. In conclusion, it was proven that dental hygienist's communication skill measurement tool has high validity and reliability. Further, this study can be used to improve dental hygienists' communication skills. Therefore, this will improve oral health of clients and manage them.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5877-5882
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• 2013

Background: The aim of the study was to determine breast cancer risk and early diagnosis applications in women aged ${\geq}50$. Materials and Methods: This cross-sectional, descriptive field study focused on a population of 4,815 in Mansuro$\breve{g}$lu with a 55.1% participation rate in screening. In the study, body mass index (BMI) was also evaluated in the calculation of breast cancer risk by the Breast Cancer Risk Assessment Tool (BCRA) (also called the "Gail Risk Assessment Tool"). The interviewers had a three-hour training provided by the researchers, during which interactive training methods were used and applications were supported with role-plays. Results: The mean age of the women participating in the study was $60.1{\pm}8.80$. Of these women, 57.3% were in the 50-59 age group, 71.7% were married, 57.3% were primary school graduates and 61.7% were housewives. Breast-cancer development rate was 7.4% in the women participating in the study. When they were evaluated according to their relationship with those with breast cancer, it was determined that 73.0% of them had firstdegree relatives with breast cancer. According to the assessment based on the Gail method, the women's breast cancer development risk within the next 5 years was 17.6%, whereas their calculated lifetime risk was found to be as low as 0.2%. Statistically significant differences (P=0.000) were determined between performing BSE-CBE and socio-demographic factors. Conclusions: It was determined that 17.6% of the participants had breast cancer risk. There was no statistically significant difference between the women with and without breast cancer risk in terms of early diagnosis practices, which can be regarded as a remarkable finding. It was planned to provide training about the early diagnosis and treatment of breast cancer for people with high-risk scores, and to conduct population-based breast cancer screening programs.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.811-815
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• 2006

The objective of this study was to evaluate the effect of electric fan installation for milk production improvement of dairy cattle in Thailand. The study was conducted using 2 small-holder dairy farms in Chiang Mai province, during April to August 2004. Electric fans were installed in front of each row of cows. Each of the two rows of cows in the barn was defined as an experimental unit, thus each farm had two experimental units. The fans were operated alternately in 7-day intervals between rows of cows within each farm during the day or between 8.00 am to 8.00 pm. Non-operation periods were used as control. Milk yields were recorded. Data on environmental temperature and humidity were obtained from Chiang Mai Meteorological Center. Result from statistically analysis of milk record suggested an interaction between lactation period and fan installation. Therefore, this interaction term of lactation period and fan installation (PERIOD_FAN) was added as a variable to the regression model. Due to the repeated data collection of milk yield from the same cow (alternate week), milk yield was analyzed by repeated measure analysis (Mixed model). Least square means were calculated for all levels and used to compare between each pair-wise values. The final data were collected from the total of 18 cows with 2,072 data. Overall means and SEM of milk yields and days in milk separated into farm were $14.7{\pm}0.06kg/day$ and $176.3{\pm}2.2days$, and $15.2{\pm}0.22kg/day$ and $202.5{\pm}3.7$ days for farm A and farm B, respectively. For multivariable analysis, only PERIOD_FAN and humidity were significantly associated with milk yield. Only the first period of lactation showed that the amount of milk yields during fan installation was higher than that of non-fan installation (p<0.05). Cows with fan installation produced approximately 1.2 kg/cow more milk than cows without fan installation during this period. In conclusion, the use of electric fan operated during the day time increased milk production of cows during the first period of lactation.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3335-3340
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• 2016

Background: Oral submucous fibrosis (OSF) is a precancerous condition with a 4 to13% malignant transformation rate. Related to the habit of areca nut chewing it is mainly prevalent in South-east Asian countries where the habit of betel quid chewing is frequently practised. On chewing, alkaloids and polyphenols are released which undergo nitrosation and give rise to N-nitrosamines which are cytotoxic agents. CYP450 is a microsomal enzyme group which metabolizes various endogenous and exogenous chemicals including those released by areca nut chewing. CYP1A1 plays a central role in metabolic activation of these xenobiotics, whereas CYP2E1 metabolizes nitrosamines and tannins. Polymorphisms in genes that code for these enzymes may alter their expression or function and may therefore affect an individuals susceptibility regarding OSF and oral cancer. The present study was therefore undertaken to investigate the association of polymorphisms in CYP1A1 m2 and CYP2E1 (RsaI/PstI) sites with risk of OSF among areca nut chewers in the Northern India population. A total of 95 histopathologically confirmed cases of OSF with history of areca nut chewing not less than 1 year and 80, age and sex matched controls without any clinical signs and symptoms of OSF with areca nut chewing habit not less than 1 year were enrolled. DNA was extracted from peripheral blood samples and polymorphisms were analyzed by PCR-RFLP method. Gene polymorphism of CYP1A1 at NcoI site was observed to be significantly higher (p = 0.016) in cases of OSF when compared to controls. Association of CYP1A1 gene polymorphism at NcoI site and the risk of OSF (Odd's Ratio = 2.275) was also observed to be significant. However, no such association was observed for the CYP2E1 gene polymorphism (Odd's Ratio = 0.815). Our results suggest that the CYP1A1 gene polymorphism at the NcoI site confers an increased risk for OSF.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.809-815
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• 1996

$Y_2O_3$-based metal-insulator-semiconductor (MIS) structure on p-Si(100) has been studied. Films were prepared by UHV reactive ionized cluster beam deposition (r-ICBD) system. The base pressure of the system was about $1 \times 10^{-9}$ -9/ Torr and the process pressure $2 \times 10^{-5}$ Torr in oxygen ambience. Glancing X-ray diffraction(GXRD) and in-situ reflection high energy electron diffracton(RHEED) analyses were performed to investigate the crystallinity of the films. The results show phase change from amorphous state to crystalline one with increasingqr acceleration voltage and substrate temperature. It is also found that the phase transformation from $Y_2O_3$(111)//Si(100) to $Y_2O_3$(110)//Si(100) in growing directions takes place between $500^{\circ}C$ and $700^{\circ}C$. Especially as acceleration voltage is increased, preferentially oriented crystallinity was increased. Finally under the condition of above substrate temperature $700^{\circ}C$ and acceleration voltage 5kV, the $Y_2O_3$films are found to be grown epitaxially in direction of $Y_2O_3$(1l0)//Si(100) by observation of transmission electron microscope(TEM). Capacitance-voltage and current-voltage measurements were conducted to characterize Al/$Y_2O_3$/Si MIS structure with varying acceleration voltage and substrate temperature. Deposited $Y_2O_3$ films of thickness of nearly 300$\AA$ show that the breakdown field increases to 7~8MV /cm at the same conditon of epitaxial growing. These results also coincide with XPS spectra which indicate better stoichiometric characteristic in the condition of better crystalline one. After oxidation the breakdown field increases to 13MV /cm because the MIS structure contains interface silicon oxide of about 30$\AA$. In this case the dielectric constant of only $Y_2O_3$ layer is found to be $\in$15.6. These results have demonstrated the potential of using yttrium oxide for future VLSI/ULSI gate insulator applications.

• Journal of Preventive Medicine and Public Health
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• v.30 no.4 s.59
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• pp.815-829
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• 1997

This study was performed to assist the employer to establish the effective program for hearing conservation of noisy industry. The study subjects were health care managers of an industry and the study industries were devided into two groups(Group I, 37 industries; have the workers diagnosed as noise-induced hearing loss, Group II, 41 industries; not have the workers diagnosed as noise-induced hearing loss) and the question method carried out through the face to face interview. The contents of questionnaire for OSHA's hearing conservation program(HCP) consisted of seven components: 5 questions of monitoring of employee noise exposures(component 1), 6 questions of the institution of engineering, work practice, and administrative controls for excessive noise(component 2), 8 questions of the provision of each overexposed employee with an individually fitted hearing protector with an adequate noise reduction rating(component 3), 14 questions of employee training and education regarding noise hazards and protection measures(component 4), 9 questions of baseline and annual audiometry(component 5), 3 questions of procedures for preventing further occupational hearning loss by an employee whenever such an event has been identified(component 6), and 1 question of recording keeping(component 7), thus total numbers of questions was 46. The numbers of statistially significant difference(p<0.05) between two groups were 2(25.0%) among 8 questions of component 3, 10(71.4%) among 14 questions of component 4, 3(33.3%) among 8 questions of component 5, 2(6.7%) among 3 questions of component 6, and 17(37.0%) among total 46 questions of questionnaire. Above results showed that the level of HCP acceptance in group I was lower than in group II. Thus employer's understanding about HCP should be precede for the effective hearing conservation program of employee and the adequate hearing protector, training and education, baseline and annual audiometry, and procedures for preventing further occupational hearning loss for hearing conservation would be more emphasized.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.384-390
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• 2012

Echocardiographic measurements of cardiac output, including the modified Simpson's method, Automated Contour Tracking(ACT) method, and left ventricular outflow method are well described methods of evaluating cardiac function due to its reliability and the benefits of its non-invasive technique in human medicine. The purpose of this study was to evaluate the accuracy of an echocardiography estimate of cardiac output in isoflurane-anesthetized beagle dogs and was to compare the ACT method to the other methods used in measurement of cardiac output. In healthy beagle dogs, cardiac output results by echocardiography estimate methods showed an excellent correlations with those by the thermodilution method (The modified Simpson's method : r = 0.815, $r^2=0.665$, y = 0.434x + 0.311 ; ACT method : r = 0.86, $r^2=0.748$, y = 0.391x + 0.242 ; ventricular outflow method : r = 0.691, $r^2=0.478$, y = 0.593x + 0.242). Among the results obtained, the ACT method showed the highest correlation coefficient. In conclusion, our study demonstrated that echocardiography estimate methods did not prove to be suitable in accurately measuring absolute cardiac output values but showed an excellent correlation with thermodilution method. Therefore, by using the measurement of cardiac output as supplemental data, echocardiography estimate methods can be used for detection and correction of hemodynamic disturbances during emergency and anesthesia in veterinary practice.

• Molecules and Cells
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• v.38 no.11
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• pp.966-974
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• 2015

Despite the presence of toll like receptor (TLR) expression in conventional $TCR{\alpha}{\beta}$ T cells, the direct role of TLR signaling via myeloid differentiation factor 88 (MyD88) within T lymphocytes on graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation (allo-SCT) remains unknown. In the allo-SCT model of C57BL/6 ($H-2^b$) ${\rightarrow}$ B6D2F1 ($H-2^{b/d}$), recipients received transplants of wild type (WT) T-cell-depleted (TCD) bone marrow (BM) and splenic T cells from either WT or MyD88 deficient (MyD88KO) donors. Host-type ($H-2^d$) P815 mastocytoma or L1210 leukemia cells were injected either subcutaneously or intravenously to generate a GVHD/GVL model. Allogeneic recipients of MyD88KO T cells demonstrated a greater tumor growth without attenuation of GVHD severity. Moreover, GVHD-induced GVL effect, caused by increasing the conditioning intensity was also not observed in the recipients of MyD88KO T cells. In vitro, the absence of MyD88 in T cells resulted in defective cytolytic activity to tumor targets with reduced ability to produce IFN-${\gamma}$ or granzyme B, which are known to critical for the GVL effect. However, donor T cell expansion with effector and memory T-cell differentiation were more enhanced in GVHD hosts of MyD88KO T cells. Recipients of MyD88KO T cells experienced greater expansion of Foxp3- and IL4-expressing T cells with reduced INF-${\gamma}$ producing T cells in the spleen and tumor-draining lymph nodes early after transplantation. Taken together, these results highlight a differential role for MyD88 deficiency on donor T-cells, with decreased GVL effect without attenuation of the GVHD severity after experimental allo-SCT.