• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.313-318
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• 2008

Dens invaginatus is a rare malformation resulting from invagination of the enamel before calcification has occurred. It is mostly found in permanent maxillary lateral incisors and mandibular teeth are rarely affected by this anomaly. The malformation is estimated to affect between 0.04 % and 10 % of people and has been associated with other abnormalities such as taurodontism, microdontia, gemination and dentinogenesis imperfecta. Dens invaginatus is classified in three types with respect to the depth of invaginatus and has a broad spectrum of morphologic variations. Invagination frequently allows the entry of irritants and microorganism, which usually lead to caries, pulp infection and pulp necrosis. Root canal treatment on such invaginatus tooth may present severe problems because of its complex anatomy of the tooth. Therefore, the early diagnosis of such malformation is crucial and preventive approach is strongly recommended.

• Journal of the Korean Society of Safety
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• v.12 no.4
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• pp.214-219
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• 1997

The mechanical seals, which are installed in rotating machines like pump and compressor, are generally used as sealing devices in the many fields of industries. The failure of mechanical seals such as leakage, crack, breakage, fast and severe wear, excessive torque, and squeaking results in big problems. To identify abnormal phenomena on mechanical seals and to propose the proper monitoring parameter for the failure of mechanical seals, sliding wear experiments were conducted. Acoustic emission, torque, and temperature were measured during experiments. Optical microstructure was observed for the wear processing after every 10 minute sliding at rotation speed of 1750 rpm and scanning electron microscopy was also observed. Except for the initial part of every experiment, the variation of acoustic emission was well coincided with torque variation during the experiments. This study concludes that acoustic emission and torque are proper monitoring parameters for the failure of mechanical seals. The intensity of acoustic emission signals is measured in root mean square voltage. Temperature of sealing face will be used as a parallel parameter for increasing the reliability of monitoring system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.324-333
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• 2018

The aim of this study was to investigate the latent classes and predictors of chronic diseases such as hypertension, dyslipidemia, arthritis, thyroid disease, depression, atopy, allergy, and diabetes. The subjects of this study were Korean citizens who participated in the Korea National Health and Nutrition Examination Survey in 2014. Stratified cluster sampling method was used with a sample size of 7,550. Latent hierarchy analysis was applied to this data. Four classes were identified. Class 1 consisted of participants with hypertension and diabetes. Class 2 consisted of participants with atopy and allergies. Class 3 consisted of participants with dyslipidemia, arthritis, thyroid disease, and depression. Class 4 consisted of participants without any chronic diseases. In comparing Class 1 to Class 4, age, physical activity, self-management, obesity, and presence of high cholesterol were found to be significant. In comparing Class 2 to Class 4, gender, age, and education level were significant. When Class 3 was compared to Class 4, gender, age, pain and discomfort, as well as high cholesterol were found to be significant. Diabetes and hypertension should be treated as comorbid conditions, applying integrated treatments involving effective drug treatment, diet, and physical activity programs. Atopy was found to be strongly correlated with allergies. Thyroid disease was found to coexist with dyslipidemia and arthritis, along with having a strong correlation to depression. Age-appropriate preventive measures can help reduce the risk of chronic diseases.

• Journal of the Korean Arthroscopy Society
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• v.11 no.1
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• pp.1-6
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• 2007

Purpose: The purpose of this preliminary report is to investigate the short term outcome of performing gel type fibrin matrix autologous chondrocyte implantation to patients who have damaged knee joint cartilage using secondary arthroscopy. Material and Methods: Six patients who have damaged knee joint cartilage were involved. The average size of defect was $5.13\;cm^2$. While performing primary arthroscopy, whole layer of cartilage bone was obtained either from the margin of damaged cartilage or the bilateral margin of a trochlea. The cartilaginous cells were obtained for culture for four to six weeks. While performing secondary minimal invasive arthrotomy, gel type fibrin matrix autologous chondrocyte was implanted on the chondral defect site. Results: 4 among 6 patients to be more than good in Modified Cincinnati Knee Scoring system. Lysholm function score was 59.5 preoperatively, and it improved to 76.25. ICRS grading by performing secondary arthroscopy revealed 4 out of 6 patients to be nearly normal. Conclusion: Gel type fibrin matrix autologous chondrocyte implantation is a treatment for cartilage defect, which takes less time to operate than the conventional implantation. In addition, this method minimizes the size of incision and allows arthroscopic surgery. However, long term follow up and more case study is thought to be necessary.

• Korean Journal of Medicinal Crop Science
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• v.7 no.4
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• pp.263-268
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• 1999

It was found that the level of alcohol concentration in both mouse and human sera can be significantly decreased up to 42% by oral administration of the mixtures of the extracts of Hovenia dulcis THUNB and Alnus japonica Steud. A single treatment of extract from Hovenia dulcis reduced the serum alcohol concentration to 32%, compared to 13% in treating the extract of Alnus japonica. Similar patterns were observed in enhancing alcohol dehydrogenase (ADH) and glutathion-S-transferase (GST) activity in the liver. The inhibition of cathepsin activity was also greatly reduced by administrating the mixture of both extracts : however, the extract of Alnus japonica did not affect the acitivity of cathepsin. It was concluded that the mixture of both extracts had synergic effect on reducing serum alcohol concentration and improving the detoxification process due to alcohol administration in the liver.

• Korean Journal of Cognitive Science
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• v.28 no.1
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• pp.65-90
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• 2017

Rewards or penalties become informative only when contingent on an immediately preceding response. Our goal was to determine if the brain responds differently to motivational events depending on whether they provide feedback with the contingencies effective for learning. Event-related fMRI data were obtained from 22 volunteers performing a visuomotor categorical task. In learning-condition trials, participants learned by trial and error to make left or right responses to letter cues (16 consonants). Monetary rewards (+500) or penalties (-500) were given as feedback (learning feedback). In random-condition trials, cues (4 vowels) appeared right or left of the display center, and participants were instructed to respond with the appropriate hand. However, rewards or penalties (random feedback) were given randomly (50/50%) regardless of the correctness of response. Feedback-associated BOLD responses were analyzed with ANOVA [trial type (learning vs. random) x feedback type (reward vs. penalty)] using SPM8 (voxel-wise FWE p < .001). The right caudate nucleus and right cerebellum showed activation, whereas the left parahippocampus and other regions as the default mode network showed deactivation, both greater for learning trials than random trials. Activations associated with reward feedback did not differ between the two trial types for any brain region. For penalty, both learning-penalty and random-penalty enhanced activity in the left insular cortex, but not the right. The left insula, however, as well as the left dorsolateral prefrontal cortex and dorsomedial prefrontal cortex/dorsal anterior cingulate cortex, showed much greater responses for learning-penalty than for random-penalty. These findings suggest that learning-penalty plays a critical role in learning, unlike rewards or random-penalty, probably not only due to its evoking of aversive emotional responses, but also because of error-detection processing, either of which might lead to changes in planning or strategy.

• Applied Microscopy
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• v.33 no.4
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• pp.299-313
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• 2003

The aim of the present study was to assess the role of protein kinase C (PKC) in the development of cardiac injury following scald burn. Sprague-Dawley rats were induced a scald burn a 15% total body surface area. Phorbol 12-myristate 13-acetate (PMA, 2 mg/kg) and bisindolylmaleimide (BIS, 0.05 mg/kg) were immediately administered i.p. after burn injury. 5 h and 24 h later, heart was removed and examined biochemical assay, ultrastructural changes and stereological analysis. The activity of serum aspartate aminotransferase was significantly increased at 5h (p<0.01) and 5h+BIS (p<0.001) after burn compared with that of control. The activity of serum creatinine was significantly decreased in PMA-treated groups after burn compared with postburn 5 h. PMA caused a decrease in MPO activity and induced wavy fibers in cardiac myocytes at postburn 5 and 24h. BIS induced contraction band, separation of intercalated disk and abnormal mitochondria in cardiac myocytes at postburn 5 and 24h. In stereological analysis, treatment of rats with PMA increased volume density of myofibril and mitochondria compared with postburn 5 and 24h. Our data suggest that the activation of PKC in scald burned heart decreases inflammation and protects the myocardium.

• Science of Emotion and Sensibility
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• v.10 no.4
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• pp.603-611
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• 2007

Initially, this study was to develop reliable and effective alcohol-associated visual cues. Alcoholic picture cues were chosen from the Normative Appetitive Picture System (NAPS). Additional images consisted of Korean beer and mild liquor was pre-tested to select the pictures that would induce craving most intensely. The images that recorded the highest scores on a scale were chosen through the pre-test. And then, the reliability and validity were examined for the selected alcohol cues from NAPS and pre-test via another psychometric test. Secondly, the study was to investigate differences in craving between subjects with alcohol use disorders (AUDs) and non-alcoholic control subjects when exposed to the alcohol visual cues. Alcohol abusers with AUD (n=9) and demographically similar non-abusers (n=9) participated in this study. After given 5cc of alcohol, subjects were exposed to different types of stimuli (i.e., alcohol, nonalcoholic beverage, and visual control pictures and one rest (cross-hair)). Craving levels were rated through self-report on a Likert scale immediately after the presentation of visual cues. Results showed statistically significant differences between the AUD group and the control group in the Obsessive Compulsive Drinking Scale (OCDS) scores, pre-sip and post-sip alcohol craving. Also, the AUD group showed significantly a higher level of craving during alcohol cues compared to the control group. In conclusion, alcohol craving induced by alcohol cues among subjects with AUD was found to be different from that of non-abusers.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.597-603
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• 2016

This study aimed to explore the protective effect of Gastrodia elata (GE) in an HCl/ethanol induced acute gastritis model by differing the steaming time. The samples GE1 (GE by steaming for 1 time) and GE9 (GE by steaming for 9 times), were selected based on the results of HPLC analysis, free radical scavenging activities, and total phenol and flavonoid contents. To evaluate the anti-inflammatory effect of GE, ICR mice were divided into 5 groups; normal mice (Nor), gastritic mice with distilled water (Con), gastritic mice with 100 mg/kg GE1, gastritic mice with 100 mg/kg GE9 and gastritic mice with 10 mg/kg sucralfate (SC). HCl/ethanol-induced gastric mucosal injury was markedly improved by GE9 treatment as observed during histological evaluation. The increased reactive oxygen species levels in the serum were diminished by GE9 treatment. Furthermore, peroxynitrite levels of the stomach tissue were decreased in the GE9-treated group. The analyses of stomach proteins indicated that GE9 treatment effectively reduced inflammatory cytokine levels as compared to that by GE1 treatment. These results suggest that GE9 improves health during acute gastritis.

• Fire Science and Engineering
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• v.30 no.4
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• pp.121-127
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• 2016

This study analyzed the structural and electrical characteristics of an iron fittings type Corrugated Stainless Steel Tubing (CSST) damaged by the Primary Current Injection Test System (PCITS). CSST consists of cladding, tube, nuts, clamp ring, flare cap, socket, and ball valve. For an evaluation of the dielectric withstand voltage, the area between the live part and non-live part of the CCST shall withstand a voltage of 220 V AC for one minute. For an evaluation of the insulation performance by 500 V DC, it is required that the insulation exceed more than $1M{\Omega}$ before the temperature rise test, $0.3M{\Omega}$ after the test. Although the average resistance of the product was $11.5m{\Omega}$, that of the product damaged at a current of 130 A by the PCITS was $11.50m{\Omega}$. Furthermore, parts of the cladding were melted and black smoke appeared when a current of 130 A applied for 10 s. After 60 s, most parts were heated and turned red. At 120 s, the parts that turned red had widened. Although it did not form a normal distribution because the P value was 0.019 with a confidential interval of 95%, it revealed outstanding characteristics with an AD (Anderson-Darling) value of 0.896 and a standard deviation of 0.5573.