• Title/Summary/Keyword: 교실 연구

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Comparison of shear bond strength according to various surface treatment methods of zirconia and resin cement types (지르코니아의 다양한 표면처리 방법과 레진시멘트 종류에 따른 전단결합강도 비교)

  • Bae, Ji-Hyeon;Bae, Gang-Ho;Park, Taeseok;Huh, Jung-Bo;Choi, Jae-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.59 no.2
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    • pp.153-163
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    • 2021
  • Purpose: The aim of this study was to evaluate the effects of four surface treatment methods to improve zirconia roughness and three types of resin cement on the shear bond strength (SBS). Materials and methods: A total of 120 zirconia blocks were randomly divided into four surface treatments: non-treatment (Control), airborne-particle abrasion (APA) with 50 ㎛ Al2O3 (APA50), APA with 125 ㎛ Al2O3 (APA125), and ZrO2 slurry (ZA). Three resin cements (Panavia F 2.0, Superbond C&B, and Variolink N) were applied to the surface-treated zirconia specimens. All specimens were subjected to SBS testing using a universal testing machine. The surface of the representative specimens of each group was observed by scanning electron microscope (SEM). SBS data were analyzed with oneway ANOVA, two-way ANOVA test and post-hoc Tukey HSD Test (α=.05). Results: In the surface treatment method, APA125, APA50, ZA, and Control showed high shear bond strength in order, but there was no significant difference between APA125 and APA50 (P>.05). Also, ZA showed significantly higher shear bond strength than Control (P<.05). In the resin cement type, Panavia F 2.0, Superbond C&B, and Variolink N showed significantly higher shear bond strength in order (P<.05). In SEM images, the zirconia surfaces of the APA50 and APA125 showed quite rough and irregular shapes, and the zirconia surface of the ZA was observed small irregular porosity and rough surfaces. Conclusion: APA and ZrO2 slurry were enhanced the surface roughness of zirconia, and Panavia F 2.0 containing MDP showed the highest shear bond strength with zirconia.

Result of Multiphasic Military Personality Inventory Among Grave's Disease in 19-Year-Old Men (19세 남성에서 그레이브스병의 다면적 군인성검사 결과)

  • Jong Hyun, Kim;Jonggook, Lee;Jeong Seok, Seo;Juhyun, Kim;Keun, Oh;Taehyun, Kim
    • Korean Journal of Psychosomatic Medicine
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    • v.30 no.2
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    • pp.196-202
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    • 2022
  • Objectives : The purpose of this study was to quantitatively assess the degree of Graves' Disease affecting mental health through the results of multiphasic military personality inventory (MPI) in 19-year-old men. Methods : We collected and analyzed the results of the MPI for 592 healthy subjects and 148 Graves' disease patients among the 19-year-old men who visited the Military Manpower Administration from February 2008 to January 2010. Results : Among demographic characteristics, both Graves' disease and control group are 19-year-old men. Educational level, socioeconomic status, parental relationship, and BMI were not statistically different between the two groups (χ2=0.089, p=0.766; χ2=5.090, p=0.278; χ2=5.988, p=0.112 ; t=-0.635, p=0.526). In the MPI, among validity scales, the score of the faking-good subscale was significantly lower in the Graves' group (t=3.507, p<0.001), but in the faking-bad and infrequency subscales scores were not significantly different between two groups (t=-1.700, p=0.090; t=-0.519, p=0.604). Among the neurosis scale, anxiety, depression, somatization, and personality disorder subscale scores were all significantly higher in Graves' disease group (t=-3.323, p<0.001; t=-4.210, p<0.001; t=-6.202, p<0.001; t=-2.872, p<0.01). Among the psychopath scale, each score of schizophrenia and paranoia subscales were not statistically different between the two groups (t=-0.158, p=0.874; t=-0.846, p=0.398). Conclusions : According to MPI result, we can confirm that Graves' disease patients in 19-year-old-men may appear features such as anxiety, depression, somatization and personality tendency (introversion or impulsivity) than the control group.

The Demands and Awareness of Pediatric Dentists on the Korean National Health Insurance System (국민건강보험에 대한 소아치과 의사들의 요구와 인식 조사 )

  • Yunhyeong, Kim;Yongkwon, Chae;Koeun, Lee;Misun, Kim;Ok Hyung, Nam;Sungchul, Choi;Hyoseol, Lee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.49 no.3
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    • pp.285-299
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    • 2022
  • The aim of this study is to investigate the awareness and perception of pediatric dentists regarding dental health insurance (DHI) system in Korea. Online surveys were sent to the members of the Korean Academy of Pediatric Dentistry (KAPD), and the responses were collected. The survey, consisting of 41 questions, was subdivided into 'general background of the respondents', 'the awareness on national health insurance (NHI) and DHI', 'the awareness on DHI pertaining to pediatric dentistry', 'issues that need improvement on DHI pertaining to pediatric dentistry', 'DHI claims', and 'the roles of KAPD in DHI'. In total, 302 responded, with a response rate of 28.9%. Excluding 2 questionnaires with insufficient answers, a total of 300 survey results were analyzed. According to the analysis, pediatric dentists thought that the coverage of DHI was not as sufficient compared to that of NHI, but were expecting its scope to broaden in the future. The satisfaction rate was higher in pit and fissure sealant and composite resin filling than in caries-detecting quantitative light-induced fluorescence. Pediatric dentists considered permanent tooth composite resin filling (65.7%) needed an increase in insurance copayment, while topical fluoride application (74.7%) to require insurance coverage. DHI claims were generally handled by dental hygienists and/or nursing assistants. Approximately half of the respondents answered that they have had experiences on appealing for insurance denials. Lastly, pediatric dentists generally had a positive attitude towards providing information for the DHI. This study is expected to be used as a sound dataset for the DHI policy development concerning pediatric dentistry.

The Induction of ROS-dependent Autophagy by Particulate Matter 2.5 and Hydrogen Peroxide in Human Lung Epithelial A549 Cells (미세먼지와 산화적 스트레스에 의한 인간 폐 상피 A549 세포에의 ROS 의존적 자가포식 유도)

  • Park, Beom Su;Kim, Da Hye;Hwangbo, Hyun;Lee, Hyesook;Hong, Su Hyun;Cheong, Jaehun;Choi, Yung Hyun
    • Journal of Life Science
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    • v.32 no.4
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    • pp.310-317
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    • 2022
  • Recently, interest in the harmful factors of particulate matter (PM), a major component of air pollution, has been increasing. In particular, PM2.5 with a diameter of less than 2.5 ㎛ is well known to induce oxidative stress accompanied by autophagy in human lung epithelial cells. However, studies on whether PM2.5 increases autophagy under oxidative stress and whether this process is reactive oxygen species (ROS)-dependent are insufficient. Therefore, in this study, we investigated whether PM2.5 promotes autophagy through the generation of ROS in human alveolar epithelial A594 cells. According to our results, cells co-treated with PM2.5 and hydrogen peroxide (H2O2) showed a lower cell viability than cells treated with each alone, which was associated with increased total and mitochondrial ROS production. The co-treatment of PM2.5 and H2O2 also increased autophagy induction, which was confirmed through Cyto-ID staining, and the expression of autophagy biomarker proteins increased. However, when ROS generation was artificially blocked by N-acetyl-L-cysteine pretreatment, the reduction in cell viability and induction of autophagy by PM2.5 and H2O2 co-treatment were markedly attenuated. Therefore, the present results suggest that PM2.5-induced ROS generation may play a critical role in autophagy induction in A549 cells.

Comparative Analysis of Antioxidant, Anti Aging and Phenolic Compounds of Different Solvent Extracts from Saccharina japonica and Costaria costata (추출용매에 따른 쇠미역과 다시마의 항산화, 항노화 활성과 페놀화합물 비교분석)

  • Hyun-Hwa Lee;Jin-Sol Kim;Jun-Han Jeong;Chun Sung Kim;Sook Young Lee
    • Korean Journal of Plant Resources
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    • v.36 no.2
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    • pp.107-121
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    • 2023
  • This study analyzed the polyphenol, flavonoid contents, antioxidant activity, anti-aging activity and phenol component contents of Saccharina japonica (SJ), Costaria costata (CC) extracts with hot water, 95% methanol, 95% prethanol for investigating possible utilization of SJ and CC extracts. The result revealed that the SJ and CC methanol extracts showed the highest polyphenol and flavonoid contents, 4.63 mg TAN/g, and 4.19 mg QUE/g respectively. Also, the SJ and CC methanol extracts showed higher antioxidant activity than prethanol and hot water extracts, whereas the ABTS radical scavenging activities were the highest in prethanol extracts (IC50 = 15.4, 10.3 ㎍/µL). In anti-aging activity for evaluating the anti-wrinkle activity and skin whitening activity, the CC methanol extracts had high collagenase inhibitory activity (88.3%), and the SJ prethanol extracts showed higher elastase inhibitory activity (19.0%) compared to other extracts. Then the tyrosinase inhibitory activity was significantly higher in the SJ and CC methanol extracts (41.8, 30.3%, respectively), whereas prethanol extracts were the lowest. To identify the phenol component contents of SJ and CC extracts, 4-hydroxybenzoic acid, naringenin, naringin and nicotinic acid were measured using LC-MS/MS. As a result, the phenol contents were the highest in SJ methanol extract (4-hydroxybenzoic acid), SJ and CC prethanol extract (naringin and naringenin) and CC prethanol extract (nicotinic acid). Lastly, the antioxidant activity of SJ and CC showed high correlations with polyphenol and flavonoid contents (R = -0.946~0.883). These results suggest that prethanol or methanol extracts of SJ and CC have higher antioxidant activities, anti-aging activity and the potential to be used as material for health functional food and cosmetics.

Protective Effects of Trifolium pratense L. Extract against H2O2-induced Oxidative Stress in HaCaT Keratinocytes (인간 피부각질세포에서 Hydrogen peroxide로 유도된 산화적 스트레스에 대한 붉은 토끼풀 추출물의 세포 보호 효과)

  • Mi Song Shin;You Kyeong Lee;Seo Young Choi;Ji Sun Hwang;Parkyong Song;Hyeon Cheal Park;Keun Ki Kim;Hong-Joo Son;Yu-Jin Kim;Kwang Min Lee
    • Journal of the Korean Applied Science and Technology
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    • v.40 no.2
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    • pp.223-232
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    • 2023
  • Oxidative stress plays a significant role in the pathogenesis of various skin conditions, resulting in cellular and tissue damage that can contribute to the development of skin tone unevenness, roughness and wrinkles. In this study, we found that Trifolium pratense L. extract (TE) attenuated oxidative-induced damage in HaCaT cells and elucidated the underlying molecular mechanism. Our finding demonstrated that TE effectively protected HaCaT cells against H2O2-induced cell death by inhibiting caspase-3 activation, downregulating Bax and upregulating Bcl-2, and attenuating the activation of three mitogen-activated protein kinases (MAPKs). Our results suggest that TE has remarkable cytoprotective properties against oxidative damage in HaCaT cells and could serve as a complementary or alternative approach to prevent and treat skin damage.

The Relationship between Social Relations and Physical Activity in the Young-old and Old-old Elderly (전·후기 노인들의 사회적 관계와 신체활동 실천과의 관련성)

  • So Youn Jeon;Sok Goo Lee
    • Journal of agricultural medicine and community health
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    • v.48 no.2
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    • pp.103-117
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    • 2023
  • Objectives: This study aims to reveal the relationship between social relations and physical activity in the young-old and old-old elderly. Methods: Data from 2020 National survey of Older Koreans were used, and a total of 10,097 subjects over the age of 65 were included in analysis. The dependent variable was physical activity, and the independent variables were social relations barrier and motivational factors. x2-test and binary logistic regression were performed for data analysis. Results: The physical activity rate in the elderly were 40.8% in the young-old and 29.2% in the old-old. The socio-demographic characteristics affecting physical activity were the young-old elderly were sex, residential area, employment status and household income, and the old-old elderly were sex, age, residential area, education level and household income. The social relations barrier factors affecting physical activity were the young-old elderly were number of close friends, family care, exercise information search and video viewing, and the old-old elderly were household type, number of close friends, participation in exercise education, exercise information search and video viewing. The social relations motivational factors affecting physical activity were the young-old elderly were call with children/relative/friend, participation in sports activity, access time from home to parks, and the old-old elderly were call with children/relative/friend, participation in sports activity, satisfaction with green spaces. Conclusions: It was found that social relations barrier and motivational factors of the elderly are important factors to consider when developing physical activity promotion strategy, and there are also difference between the age of the elderly.

Effects of Thermotherapy for Life Care in the Elderly with Chronic Neck Pain (만성 목통증 노인환자의 라이프케어를 위한 온열치료의 효과 연구)

  • Lee, Jong-Min;Shin, Ho-Jin;Kim, Sung-Hyeon;Roh, Young-Chae;Jung, Kyoung-Sim;Hahm, Suk-Chan;Lee, Sung-Jae
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.8
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    • pp.635-645
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    • 2019
  • Non-specific chronic neck pain (CNP) is a prevalent disorder and often accompany with pain, fatigue, reduced range of motion (ROM), and hand function. Although various types of drug are commonly used to manage the symptoms following CNP, there is a need for therapeutic exercise and alternative medicine interventions that have few side effects or are easy to apply. Present study investigated the effects of salt pack and neck exercise for life care of the elderly with non-specific CNP. Sixteen patients with non-specific CNP were recruited and randomly assigned into two groups: the intervention group (n=8) or the control group (n=8). All patients performed neck self-exercise for 30 min/day, 5 times a week for 1 week. And the subjects in the intervention group additionally received salt hot pack for 20 min per session. Visual analogue scale (VAS) and pain pressure threshold (PPT) using algometer were used to assess pain intensity (primary outcome). ROM of shoulder joint and grip strength were measured to test shoulder and hand function (secondary outcome). There were significant improvements in the intervention group (p<.05), while the subjects in the control group did not show a significant change after intervention (p>.05). Also, the intervention group show significant differences in VAS and PPT compared to the control group (p<.05). Thus, our results demonstrated that salt pack and neck exercise have a positive effect for life care in elderly patients with non-specific CNP.

Impact of Gender Differences in Elderly Patients with Acute Myocardial Infarction (고령의 급성 심근경색증 환자에서 성별에 따른 영향)

  • Seol, Soo Young;Jeong, Myung Ho;Lee, Seung Hun;Sohn, Seok-Joon;Cho, Jae Yeong;Kim, Min Chul;Sim, Doo Sun;Hong, Young Joon;Park, Hyung Wook;Kim, Ju Han;Ahn, Youngkeun;Cho, Jeong Gwan;Park, Jong Chun
    • The Korean Journal of Medicine
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    • v.94 no.1
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    • pp.96-106
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    • 2019
  • Background/Aims: It is well known that gender differences are associated with clinical outcomes in patients with acute myocardial infarction (AMI). However, it is not clear whether gender differences affect the prognosis of elderly patients with AMI. Methods: We analyzed the incidence of in-hospital complications and mortality in the Korea Acute Myocardial Infarction Registry-National Institutes of Health from November 2011 to June 2015. This study included elderly patients (≥ 75 years) diagnosed with AMI. Results: A total of 2,953 patients were eligible for this study. Among them, 1,529 (51.8%) patients were female, and the mean age of the female group was older than that of the male group (80.7 ± 4.4 vs. 79.6 ± 4.0 years, respectively, p < 0.001). Elderly females utilized emergency medical services less frequently compared with elderly males (11.5 vs. 15.4%, respectively, p < 0.001). Elderly female AMI patients had a similar rate of in-hospital mortality compared with elderly males (7.1 vs. 8.4%, respectively, p = 0.196). The rate of major cardiac adverse events (MACEs) was lower in elderly females than males during a 12-month follow-up (hazard ratio [HR] 1.19, 95% confidence interval [CI] 1.00-1.41, p = 0.045). According to multivariate analysis, the male gender is an independent factor for predicting 1-year MACEs (HR 1.37, 95% CI 1.14-1.65, p < 0.001). Conclusions: No significant differences in peri-procedural complications or in-hospital mortality were observed between male and female elderly patients with AMI. However, elderly female patients had a more favorable prognosis than male patients during a 1-year clinical follow-up.

Radiomics Analysis of Gray-Scale Ultrasonographic Images of Papillary Thyroid Carcinoma > 1 cm: Potential Biomarker for the Prediction of Lymph Node Metastasis (Radiomics를 이용한 1 cm 이상의 갑상선 유두암의 초음파 영상 분석: 림프절 전이 예측을 위한 잠재적인 바이오마커)

  • Hyun Jung Chung;Kyunghwa Han;Eunjung Lee;Jung Hyun Yoon;Vivian Youngjean Park;Minah Lee;Eun Cho;Jin Young Kwak
    • Journal of the Korean Society of Radiology
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    • v.84 no.1
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    • pp.185-196
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    • 2023
  • Purpose This study aimed to investigate radiomics analysis of ultrasonographic images to develop a potential biomarker for predicting lymph node metastasis in papillary thyroid carcinoma (PTC) patients. Materials and Methods This study included 431 PTC patients from August 2013 to May 2014 and classified them into the training and validation sets. A total of 730 radiomics features, including texture matrices of gray-level co-occurrence matrix and gray-level run-length matrix and single-level discrete two-dimensional wavelet transform and other functions, were obtained. The least absolute shrinkage and selection operator method was used for selecting the most predictive features in the training data set. Results Lymph node metastasis was associated with the radiomics score (p < 0.001). It was also associated with other clinical variables such as young age (p = 0.007) and large tumor size (p = 0.007). The area under the receiver operating characteristic curve was 0.687 (95% confidence interval: 0.616-0.759) for the training set and 0.650 (95% confidence interval: 0.575-0.726) for the validation set. Conclusion This study showed the potential of ultrasonography-based radiomics to predict cervical lymph node metastasis in patients with PTC; thus, ultrasonography-based radiomics can act as a biomarker for PTC.