• Journal of Oral Medicine and Pain
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• v.37 no.4
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• pp.195-203
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• 2012

Recurrent aphthous ulcer(RAU) is the most frequent form of oral ulceration with a prevalence in the general population ranging between 5% and 60%. The peak age of onset is between 10 and 19 years of age, and it can persist into adulthood and throughout the patient's lifespan, with no gender predilection. The disease is characterized clinically into three types: minor aphthous ulcer, major aphthous ulcer and herpeticform ulcers. The cause of RAU is unknown and thought to be multifactorial with many triggers or precipitating factors that include familial tendency or genetic predisposition, allergy, medications, hormones, stress or anxiety, and immunologic abnormalities. The need for consideration of psychological factors in the pathogenesis of oral disease has been increasingly acknowledged over the last decades and many studies have highlighted the psycho-social impact of oral conditions. In this study, we tried to evaluate the influence of emotional stress in RAU. There were thirty patients with a clinical diagnosis of RAU and other subjects who did not show any signs of systemic disorders include RAU. They are evaluated by using modified Holmes and Rahe's Social Readjustment Rating Scale (SRRS). As a result, a significantly higher level of stress was found in the RAU patients than the control group. Therefore it can be concluded that psychological stressors play an important role in the RAU.

• Geophysics and Geophysical Exploration
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• v.9 no.1
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• pp.50-59
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• 2006

The risk of fault reactivation in the Gippsland Basin was calculated using the FAST (Fault Analysis Seal Technology) technique, which determines fault reactivation risk by estimating the increase in pore pressure required to cause reactivation within the present-day stress field. The stress regime in the Gippsland Basin is on the boundary between strike-slip and reverse faulting: maximum horizontal stress $({\sim}\;40.5\;Mpa/km)$ > vertical stress (21 Mpa/km) ${\sim}$ minimum horizontal stress (20 MPa/km). Pore pressure is hydrostatic above the Campanian Volcanics of the Golden Beach Subgroup. The NW-SE maximum horizontal stress orientation $(139^{\circ}N)$ determined herein is broadly consistent with previous estimates, and verifies a NW-SE maximum horizontal stress orientation in the Gippsland Basin. Fault reactivation risk in the Gippsland Basin was calculated using two fault strength scenarios; cohesionless faults $(C=0;{\mu}=0.65)$ and healed faults $(C=5.4;\;{\mu}=0.78)$. The orientations of faults with relatively high and relatively low reactivation potential are almost identical for healed and cohesionless fault strength scenarios. High-angle faults striking NE-SW are unlikely to reactivate in the current stress regime. High-angle faults oriented SSE-NNW and ENE-WSW have the highest fault reactivation risk. Additionally, low-angle faults (thrust faults) striking NE-SW have a relatively high risk of reactivation. The highest reactivation risk for optimally oriented faults corresponds to an estimated pore pressure increase (Delta-P) of 3.8 MPa $({\sim}548\;psi)$ for cohesionless faults and 15.6 MPa $({\sim}2262\;psi)$ for healed faults. The absolute values of pore pressure increase obtained from fault reactivation analysis presented in this paper are subject to large errors because of uncertainties in the geomechanical model (in situ stress and rock strength data). In particular, the maximum horizontal stress magnitude and fault strength data are poorly constrained. Therefore, fault reactivation analysis cannot be used to directly measure the maximum allowable pore pressure increase within a reservoir. We argue that fault reactivation analysis of this type can only be used for assessing the relative risk of fault reactivation and not to determine the maximum allowable pore pressure increase a fault can withstand prior to reactivation.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.1002-1007
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• 2012

The considerable portion of energy demand has been satisfied by the combustion of fossil fuel and the consequent $CO_2$ emission was considered as a main cause of global warming. As a technology option for $CO_2$ emission mitigation, absorption process has been used in $CO_2$ capture from large scale emission sources. To set up optimal operating parameters in $CO_2$ absorption and solvent regeneration units are important for the better performance of the whole $CO_2$ absorption plant. Optimal operating parameters are usually selected through a lot of actual operation data. However theoretical approach are also useful because the arbitrary change of process parameters often limited for the stability of process operation. In this paper, a theoretical approach based on vapor-liquid equilibrium was proposed to estimate optimal operating conditions of $CO_2$ absorption process. Two $CO_2$ absorption processes using 12 wt% aqueous $NH_3$ solution and 20 wt% aqueous MEA solution were investigated in this theoretical estimation of optimal operating conditions. The results showed that $CO_2$ loading of rich absorbent should be kept below 0.4 in case of 12 wt% aqueous $NH_3$ solution for $CO_2$ absorption but there was no limitation of $CO_2$ loading in case of 20 wt% aqueous MEA solution for $CO_2$ absorption. The optimal regeneration temperature was determined by theoretical approach based on $CO_2$ loadings of rich and lean absorbent, which determined to satisfy the amount of absorbed $CO_2$. The amount of heating medium at optimal regeneration temperature is also determined to meet the difference of $CO_2$ loading between rich and lean absorbent. It could be confirmed that the theoretical approach, which accurately estimate the optimal regeneration conditions of lab scale $CO_2$ absorption using 12 wt% aqueous $NH_3$ solution could estimate those of 20 wt% aqueous MEA solution and could be used for the design and operation of $CO_2$ absorption process using chemical absorbent.

• Korean Journal of Health Education and Promotion
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• v.14 no.1
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• pp.73-95
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• 1997

Elderly problem from being aging society, especially health related problem of the elderly is very serious in many parts of this country. The reason is that most of geriatric disease are chronic and debilitating. The cause of chronic and debilitating disease are bad lifestyle and wrong health habit. Health is affected by a result of interaction of environment and human being. Because of difference of lifestyle between a city and a farm village, health behavior and health status of urban elderly and rural elderly may be dissimilar. Thus the purpose of this study was to grasp health behavior and health status, to identify the factors that effect on health status of the elderly. The subfects for this study, 488 persons aged 60 and over who live in Seoul or Cheonbuk Province. The preliminary survey was carried out from Aug. 19, to Aug. 22, 1996. With complement of questions, main survey was carried out from Sep. 29, to Oco. 10, 1996. The data was analysed by using in SPSS/PC+ program. The results were as follows. 1. General Characteristics 1) In the individual characteritics of the respondents, Seoulites aged 80 and over were 24.7%, the average age was 73.14 years old and rural residents aged 60-69 were 63.7%, the average age was 68.90 years old. In Seoul, 142 men and 101 women were respondents. In Cheonbuk Province, 101 men and 144 women were answered. In Seoul, those who graduated form elementary school were 35.4%, in farming region, illiteracy persons were 44.9%. In Seoul, 47.7% of respondents had spouse and in farming village, 66.1% of respondents had spouse. 39.0% of respondents who's imcome type was independent were Seoulite, and 66.1% of respondents who's income type was independent were rural residents. Employed persons in Seoul and in rural region were 16.9% and 62.0%. 2. Health Behavior 1) For the health behavior total score, the difference by region was not statistically significant. But the score of individual item was different and statistically significant. 2) For the Seoulites, younger person(p〈0.01), the female(p〈0.001) showed better health behavior and for the farming village residents, younger person(p〈0.01), the female(p〈0.01), independent income type(p〈0.05), employed person(p〈0.05) showed better health behavior. 3. Health Status 1) For the self-rated health status total score, the difference by region was statistically significant and individual item score was different and statistically significant. For ADL and IADL total score, the difference by region was not statistically significant, but individual item score was different and statistically significant. 2) For the Seoulites, woman(p〈0.05), lower education(p〈0.00l), independent income type(p〈0.05) showed higher score in self-rated health status. For rural residents, woman(p〈0.05), lower education(p〈0.01), independent Income type(p〈0.001) showed higher score in self-rated health status. For the Seoul residents, younger person(p〈0.001), employed(p〈0.05) showed higher score in ADL and IADL, and for the farm area residents, younger person(p〈0.001), higher education(p〈0.01), having spouse(p〈0.001), family type(p〈0.01) showed higher score In ADL and IADL. 3) For the Seoulites, drinking(p〈0.05), breakfast(p〈0.05), exercise(p〈0.05) and for the rural residents, drinking(p〈0.05), deep sleeping(p〈0.05), exercise(p〈0.01), washing hands before meal(p〈0.01) showed higher score In self-rated health status. For the Seoulites, deep sleeping(p〈0.05), exercise(p〈0.05) and for the farm village residents, fruit(p〈0.05), deep sleeping(p〈0.05), exercise(p〈0.001) showed higher score in ADL and IADL. We carried out this study to analyze the effectiveness through health education program in short term which was performed to use the special subject activities. This study was conducted on 63 students who were first grade in S Junior High School from Dec. 1995 to Feb. 1996. To analyze the effectiveness, we performed the Pretest, 1st Posttest, and 2nd Posttest for learned health knowledge. The results were as follows: 1. Most of the students(69.8%) responded that their health were good, and they got the information for health through Mass Com.. The students who had experience of health education were 15.9%, and the 77.8% of the respondents needed the health education. 2. The means of health knowledge on tests were 18.2(Pretest), 21.5(1st Posttest), and 21.4(2nd Posttest). Increase of health knowledge between Pretest and 1st Posttest was 10.9%. 3. The mean of differences between Pretest and 1st Posttest was 3.26, it was significant(p〈0.01). And the mean of differences between Pretest and 2nd Posttest was 3.19, it was significant(p〈0.01);however, the mean of differences between 1st Posttest and 2nd Posttest was not significant(p=0.2514). 4. The significant main contents were Health Facilities(d=0.42), Pregnancy and Labor(d=0.39), Hygiene(d=0.35), Safety Education(d=0.66), and Drug Abuse(d=0.60)(p〈0.01).

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.177-185
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• 2014

Purpose: This study is designed to investigate the various impacts of different types of scaler tips such as cooper alloy base tip and the others on the surface roughness of teeth and implant by the method which is currently in clinical use. Materials and methods: Four different types of disc shaped porcelain, titanium, zirconia, and Type III gold alloy dental materials sized 15 mm diameter, 1.5 mm thickness were used for the experiment. Plastic hand curette (Group PS), cooper alloy new tip (Group IS), and stainless steel tip (Group SS) were used as testing appliances. A total of 64 specimens were used for this study; Four specimens for each material and appliance group. Surface roughness was formed with 15 degree angle in ultrasonic scaler tip and with 45 degree angle in hand curette of instrument tip and the specimen surface with 5 mm long, one horizontal-reciprocating motion per second for 30 seconds by 40 g force. To survey the surface roughness of each specimen, a field emission scanning electron microscope, an atomic force microscope, and a surface profiler were used. (Ra, ${\mu}m$). Results: According to SEM, most increased surface roughness was observed in SS group while IS groups had minimal roughness change. Measurement by atomic force microscope presented that the surface roughness of SS group was significantly greater than those of PS, IS and control groups in the type III gold alloy group (P<.05). IS group showed lesser surface roughness changes compared to SS group in porcelain and gold alloy group (P<.05). According to surface profiler, surface roughness of SS group showed greater than those of PS, IS and control groups and IS group showed lesser than those of SS group in all specimen groups. Type III gold alloy group had large changes on surface roughness than those of porcelain, titanium, zirconia (P<.05). Conclusion: The result of this study showed that newly developed copper alloy scaler tip can cause minimal roughness impacts on the surface of implant and dental materials; therefore this may be a useful alternative for prophylaxis of implant and restored teeth.

• Clinical and Experimental Pediatrics
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• v.51 no.5
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• pp.487-491
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• 2008

Purpose : Although Mycoplasma pneumoniae (M. pneumoniae) infection can cause wheezing in non-asthmatic children, the mechanisms of this symptom remain unclear. Vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis and vascular permeability, and is also known to be elevated in cases of chronic pulmonary disease such as asthma. We hypothesized that VEGF may increase in children with acute M. pneumoniae pneumonia and wheezing. Methods : Nine patients with clinical and laboratory evidence of acute M. pneumoniae pneumonia were enlisted from children admitted to Korea University Hospital. They had had more than one episode of wheezing during the illness, which was confirmed by a physician; they comprised the wheezer group. The individuals with M. pneumoniae pneumonia without wheezing were 63 in number, and they comprised the non-wheezer group. Patients with a history of asthma or who had received asthma medications were excluded. Serum concentrations of VEGF, total IgE, eosinophil cationic protein (ECP), and peripheral blood eosinophil counts were measured. Results : The serum VEGF concentrations were higher in the wheezer group ($mean{\pm}SD$; $650.2{\pm}417.9pg/mL$) than in the non-wheezer group ($376.5{\pm}356.2pg/mL$, P=0.049). M. pneumoniae antibody (1:1,380 vs. 1:596, P=0.048) and serum total IgE (591.8 IU/mL vs. 162.2 IU/mL, P=0.032) were higher in the wheezer group than in the non-wheezer group. There were no differences between the two groups in terms of serum ECP concentration or blood eosinophil count. Conclusion : In the presence of wheezing, serum VEGF concentrations were higher in the children with M. pneumoniae pneumonia. This finding suggests that VEGF may associate with wheeze-related symptoms in children with acute M. pneumoniae pneumonia.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.266-274
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• 2010

This study aim to investigate fundamentally the growth and physiological responses of tomato plants in responses to two different levels of water deficit, a weak drought stress (-25 kPa) and a severe drought stress (-100 kPa) in soil. The two levels of water deficit were maintained using a micro-irrigation system consisted of soil sensors for the real-time monitoring of soil water content and irrigation modules in a greenhouse experiment. Soil water contents were fluctuated throughout the 30 days treatment period but differed between the two treatments with the average -47 kPa in -25 kPa set treatment and the -119 kPa in -100 kPa set treatment. There were significant differences in plant height between the two different soil water statuses in plant height without differences of the number of nodes. The plants grown in the severe water-deficit treatment had greater accumulation of biomass than the plants in the weak water-deficit treatment. The severe water-deficit treatment (-119 kPa) also induced greater leaf area and leaf dry weight of the plants than the weak water-deficit treatment did, even though there was no difference in leaf area per unit dry weight. These results of growth parameters tested in this study indicate that the severe drought could cause an adaptation of tomato plants to the drought stress with the enhancement of biomass and leaf expansion without changes of leaf thickness. Greater relative water content of leaves and lower osmotic potential of sap expressed from turgid leaves were recorded in the severe water deficit treatment than in the weak water deficit treatment. This finding also postulated physiological adaptation to be better water status under drought stress. The drought imposition affected significantly on photosynthesis, water use efficiency and stomatal conductance of tomato plants. The severe water-deficit treatment increased PSII activities and water use efficiency, but decreased stomatal conductance than the weak water-deficit treatment. However, there were no differences between the two treatments in total photosynthetic capacity. Finally, there were no differences in the number and biomass of fruits. These results suggested that tomato plants have an ability to make adaptation to water deficit conditions through changes in leaf morphology, osmotic potentials, and water use efficiency as well as PSII activity. These adaptation responses should be considered in the screening of drought tolerance of tomato plants.

• Journal of Preventive Medicine and Public Health
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• v.31 no.2 s.61
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• pp.275-284
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• 1998

Activities of enzymes involved in the metabolism of various carcinogenic xenobiotics is one of the most important host factors for cancer occurrence. N-acetyltransferase (NAT) and glutathione S-transferases (GST) are enzymes which .educe the toxicity of activated carcinogenic metabolites. Slow N-acetylation and lack of GST mu (GSTMI) were reported as risk factors of bladder cancer. GST theta (GSTT1), which is another type of GST, was reported to be deleted at higher proportion among Koreans. Since cause of bladder cancer is not fully explained by single risk factor, many kinds of enzymes would be involved in the metabolism of carcinogens excreted in urine. This study was performed to investigate whether the polymorphisms of NAT2, GSTM1 and GSTT1 are risk factors of bladder cancer and to evaluate the effects of their interaction on bladder cancer development. Sixty-seven bladder cancer and 67 age- and sex-matched non-cancer patients hospitalized in Chungbuk National University Hospital from March to December 1996, are the subjects of this case-control study. Questionnaire interview was done and the genotypes of NAT2, GSTM1 and GSTT1 were identified using PCR methods with DNA extracted from venous blood. The effects of the polymorphism of NAT2 and GSTM1 and their interaction on bladder cancer were statistically tested after controlling the other risk factors. The frequencies of slow, intermediate, and rapid acetylators were 3.0%, 38.8%, and 58.2% to. the cases, and 7.6%, 40.9%, and 51.5% for the controls, respectively. The risk of bladder cancer was not associated with the increase of NAT2 activity($\chi^2_{trend}=1.18$, P-value>0.05). GSTM1 was deleted in 68.7% of the cases and 49.3% of the controls ($\chi^2=5.21$, P-value<0.05), and the odds ratio (95% CI) was 2.23 (1.12 - 4.56). GSTT1 deletion, the .ate of which were 26.9% for the bladder cancer patients and 43.3% for the controls, was a significant protective factor against bladder cancer. Smoking history turned out to be insignificant as a risk factor of bladder cancer (OR=1.85, 95% CI: 0.85 - 4.03), and occupation could not be tested because of the extremely small number of occupational history related to the increase of bladder cancer. In multiple logistic analysis controlling the effects of other risk factors, GSTM1 deletion was the only significant risk factor for bladder cancer (OR: 2.56, 95% CI: 1.22-5.36, P-value<0.05), but slow acetylation and GSTT1 deletion were not. These results suggest that GSTM1 deletion may be a significant risk factor of bladder cancer. Since there have been much debates on causal relationship between slow acetylation and GSTT1 deletion, and bladder cancer, further studies are needed.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.3-6
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• 2012

Purpose : Samsung medical ceter shall find a cause of the interference factor and suggest a solution for it. Materials and Methods : A sample of $^{18}F$-FDG, radioactive pharmaceuticals produced by TRACERlab MX and FASTlab synthesizer. Gel-clot method uses Positive control tube and single test tube. Kinetic chromogenic method uses ENDOSAFE-PTS produced by Charles River. Results : According to Gel clot method of Endotoxin Tests at FASTlab, both turbidity and viscosity increased at 40-fold dilution and Gel clot was detected. In case of TRACERlab MX, Gel clot was detected in most of samples but intermittently not in a few of them. When using ENDOSAFE-PTS, sample CV (Coefficient of Variation) of FASTlab is 0% at all dilution rates whereas spike CV is 0% at 1-fold dilution, 0~35% at 10-fold, 3.6~12.9% at 20-fold, 5.2~7.1% at 30-fold, 1.1~17.4% at 40-fold, spike recovery; 0% at one-fold, 25 ~ 58% at 10-fold, 50 ~ 86% at 20-fold, 70~92% at 30-fold, and 75~120% at 40-fold. Sample CV of TRACERlab MX, is 0% at all dilution rates whereas spike CV is 1.4~4.8% at one-fold dilution, 0.6~19.9% at 10-fold, spike recovery; 35~72% at one-fold dilution and 77~107% at 10-fold. Conclusion : Gel clot does not seem to occur probably to H3PO4 which engages in bonding with Mg2+ion contributing gelation inside PCT. Dilution which is identical to reducing the amount of H3PO4, could remove interfering effects accordingly. Spike recovery was obtained within 70~150% - recommended values of supplier - at 40-fold dilution even in kinetic chromogenic method.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.46-53
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• 2010

Purpose: The static image of nuclear medicine study should be acquired without a motion, however, it is difficult to acquire static image without movement for the serious patients, advanced aged patients. These movements cause decreases in reliability for quantitative and qualitative analysis, therefore re-examination was inevitable in the some cases. Consequently, in order to improve the problem of motion artifacts, the authors substituted the dynamic acquisition technique for the static acquisition, using motion correction. Materials and Methods: A capillary tube and IEC body phantom were used. First, the static image was acquired for 60 seconds while the dynamic images were acquired with a protocol, 2 sec/frame${\times}$30 frames, under the same parameter and the frames were summed up into one image afterwards. Also, minimal motion and excessive motion were applied during the another dynamic acquisition and the coordinate correction was applied towards X and Y axis on the frames where the motion artifact occurred. But the severe blurred images were deleted. Finally, the resolution and counts were compared between the static image and the summed dynamic images which before and after applying motion correction, and the signal of frequency was analysed after frequency spatial domain was transformed into 2D FFT. Supplementary examination, the blind test was performed by the nuclear medicine department staff. Results: First, the resolution in the static image and summed dynamic image without motion were 8.32 mm, 8.37 mm on X-axis and 8.30 mm, 8.42 mm on Y-axis, respectively. The counts were 484 kcounts, 485 kcounts each, so there was nearly no difference. Secondly, the resolution in the image with minimal motion applying motion correction was 8.66 mm on X-axis, 8.85 mm on Y-axis and had 469 kcounts while the image without motion correction was 21.81 mm, 24.02 mm and 469 kcounts in order. So, this shows the image with minimal motion applying motion correction has similar resolution with the static image. Lastly, the resolution in the images with excessive motion applying motion correction were 9.09 mm on X-axis, 8.83 mm on Y-axis and had 469 kcounts while the image without motion correction was 47.35 mm, 40.46 mm and 255 kcounts in order. Although there was difference in counts because of deletion of blurred frames, we could get similar resolution. And when the image was transformed into frequency, the high frequency was decreased by the movement. However, the frequency was improved again after motion correction. In the blind test, there was no difference between the image applying motion correction and the static image without motion. Conclusion: There was no significant difference between the static image and the summed dynamic image. This technique can be applied to patients who may have difficulty remaining still during the imaging process, so that the quality of image can be improved as well as the reliance for analysis of quantity. Moreover, the re-examination rate will be considerably decreased. However, there is a limit of motion correction, more time will be required to successfully image the patients applying motion correction. Also, the decrease of total counts due to deletion of the severe blurred images should be calculated and the proper number of frames should be acquired.