• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.388-395
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• 1997

Maintaining the original canal path during instrumentation is a challenge in narrow curved canals. This study compared the maintenance of the original canal path of curved root canals during instrumentation with two kinds of stainless steel K-files(Brassler USA & Mani Japan), K-flexofiles(Maillefer Swiss) and Ni-Ti files(Brassler USA, Savannah, GA) using circumferential filing technique to # 40 MAF on 60 extracted human molars. Buccal and mesial canals with minimal initial curvature of 20 degrees were used. The maximal initial curvature was 41.5 degrees. Sixty curved canals divided into four groups according to file type(Group 1 : Ni-Ti file, Group 2 : K-flexofile, Group 3: K-file(Brassler), Group 4 : K-file(Mani)). Radiographs of canals were obtained before and after canal shaping. And postoperative radiographs were compared with preoperative radiographs using superimposition method. Data analysis was performed using Covariance analysis and paired-comparison test. The results observed were as follow ; 1. The angle of curvature was better maintained with Ni-Ti file than with stainless steel files. (p<0.01) 2. There was no significant difference in maintaining canal curvature between K-flexofile, Brassler$^{(R)}$ K-file and Mani$^{(R)}$ K-file, although there was some differences in mean values of postoperative canal curvature. 3. Paired-comparison t test revealed significant differences within each of the three stainless steel file types when comparing the mean differences before and after instrumentation, but no significant differences were observed within Ni-Ti file group.

• 한국환경과학회지
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• 제22권7호
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• pp.855-862
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• 2013

Although antioxidant activities of Korean traditional fermented foods were reported by many researchers, study on antioxidant activity of microorganism originated from Korean traditional fermented foods was little. Therefore, we improved condition for antioxidant production by a bacterium isolated from home-made Chungkookjang. We selected a bacterial strain, which showed the highest antioxidative activity, from Chungkookjang and then named GJ. The selected GJ strain was identified as Bacillus methylotrophicus by alignment data of 16S rRNA gene nucleotide sequences. Improved medium compositions for DPPH radical scavenging activity were 0.25% sucrose, 1% peptone, 0.01% $MgSO_4{\cdot}7H_2O$ and initial pH 6.5, respectively. Optimal culture conditions were $30^{\circ}C$, 200 rpm and 4% inoculum volume, respectively. In improved conditions, DPPH radical scavenging activity of GJ reached to 91% in a short time. The strain GJ also possessed ACE inhibition and other antioxidative activities; ACE inhibition activity (49.4%), ABTS radical scavenging activity (99.8%), metal chelating activity (67.9%), SOD-like activity (36.5%) and reducing power ($A_{700}$ = 5.982) were observed, respectively. Therefore, our results suggest that B. methylotrophicus GJ strain may be potential candidate for functional foods, cosmetic products for anti-aging and medicine for diseases caused by oxidative stress.

• Annals of dermatology
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• 제30권6호
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• pp.645-652
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• 2018

Background: Adiponectin, an adipokine secreted from adipocytes, affects energy metabolism and also shows anti-diabetic and anti-inflammatory properties. Recent studies have reported that adiponectin plays a role in regulating skin inflammation. Objective: This study aimed to investigate the effect of adiponectin on the expression of filaggrin (FLG) in normal human epidermal keratinocytes (NHEKs). Methods: NHEKs were serum-starved for 6h before being treated with adiponectin. Afterward, cell viability was assessed by MTT assay. We also treated with calcium, interleukin (IL)-4, and IL-13 to provide positive and negative comparative controls, respectively. Gene mRNA expression was quantified using real time reverse transcription polymerase chain reaction, and protein expression was evaluated using Western blot. To evaluate the relationship among mitogen-activated protein kinases (MAPKs), activator protein 1 (AP-1), and FLG, we also treated cells with inhibitors for MAPKs JNK, p38, and ERK1/2. Results: FLG and FLG-2 mRNA expression in NHEKs significantly increased after treatment with $10{\mu}g/ml$ adiponectin. Adiponectin also restored FLG and FLG-2 mRNA expression that was otherwise inhibited by treatment with IL-4 and IL-13. Adiponectin induced FLG expression via AP-1 and MAPK signaling. Conclusion: Adiponectin positively regulated the expression of FLG and could be useful as a therapeutic agent to control diseases related to disrupted skin barrier function.

• 대한치과교정학회지
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• 제51권5호
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• pp.313-320
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• 2021

Objective: The purpose of this study was to evaluate the effects of chewing gum and low-level laser therapy in alleviating orthodontic pain induced by the initial archwire. Methods: Patients with 3-6 mm maxillary crowding who planned to receive non-extraction orthodontic treatment were recruited for the study. Sixty-three participants (33 females and 30 males) were randomly allocated into three groups: laser, chewing gum, and control. In the laser group, a gallium aluminum arsenide (GaAlAs) diode laser with a wavelength of 820 nm was used to apply a single dose immediately after orthodontic treatment began. In the chewing gum group, sugar-free gum was chewed three times for 20 minutes-immediately after starting treatment, and at the twenty-fourth and forty-eighth hours of treatment. Pain perception was measured using a visual analog scale at the second, sixth, and twenty-fourth hours, and on the second, third, and seventh days. Results: There were no statistically significant differences between the groups at any measured time point (p > 0.05). The highest pain scores were detected at the twenty-fourth hour of treatment in all groups. Conclusions: Within the limitations of the study, we could not detect whether low-level laser therapy and chewing gum had any clinically significant effect on orthodontic pain. Different results may be obtained with a higher number of participants or using lasers with different wavelengths and specifications. Although the study had a sufficient number of participants according to statistical analysis, higher number of participants could have provided more definitive outcomes.

• Clinical and Experimental Pediatrics
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• 제62권1호
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• pp.36-41
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• 2019

Purpose: In this study, we investigated the clinical features and prognostic factors of early-onset sepsis (EOS) in neonatal intensive care unit (NICU) patients. Methods: A retrospective analysis was conducted on medical records from January 2010 to June 2017 (7.5 years) of a university hospital NICU. Results: There were 45 cases of EOS (1.2%) in 3,862 infants. The most common pathogen responsible for EOS was group B Streptococcus (GBS), implicated in 10 cases (22.2%), followed by Escherichia coli, implicated in 9 cases (20%). The frequency of gram-positive sepsis was higher in term than in preterm infants, whereas the rate of gram-negative infection was higher in preterm than in term infants (P<0.05). The overall mortality was 37.8% (17 of 45), and 47% of deaths occurred within the first 3 days of infection. There were significant differences in terms of gestational age (26.8 weeks vs. 35.1 weeks) and birth weight (957 g vs. 2,520 g) between the death and survival groups. After adjustments based on the difference in gestational age and birth weight between the 2 groups, gram-negative pathogens (odds ratio [OR], 42; 95% confidence interval [CI], 1.4-1,281.8) and some clinical findings, such as neutropenia (OR, 46; 95% CI, 1.3-1,628.7) and decreased activity (OR, 34; 95% CI, 1.8-633.4), were found to be associated with fatality. Conclusion: The common pathogens found to be responsible for EOS in NICU patients are GBS and E. coli. Gram-negative bacterial infections, decreased activity in the early phase of infection, and neutropenia were associated with poor outcomes.

• 한국식품영양학회지
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• 제34권3호
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• pp.255-262
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• 2021

Centella asiatica (CA) is a vegetable that has been used for medicinal purposes for a long time, but it is not well known in Korea. In this study, the approximate analysis, physicochemical properties, free sugars, free amino acids and minerals of native and improved CA cultivated in Chungju area were measured. And the antioxidant contents and activities of CA solvent extracts were measured. There was no significant difference between native and improved species. As for the characteristics of CA, it was confirmed that the improved species had a large weight, size and a tough texture. Glucose was detected in native CA, fructose, glucose and sucrose were detected in improved species. A total of 15 free amino acids were detected and the content was slightly higher in improved species than in native species. The mineral content in CA was slightly higher in the improved species, and the detected minerals were Na, P, Ca, K, Mg and Fe. Polyphenols, ascorbic acid and flavonoids in each extraction solvent (water, 70% and 100% ethanol) were all higher in the improved species than in native species. And it was found that the antioxidant activities of ethanol extracts were higher than that of water.

• Investigative Magnetic Resonance Imaging
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• 제26권2호
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• pp.135-149
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• 2022

Purpose: To assess clinically significant imaging findings of malignant intramammary lymph nodes (IMLNs) in breast cancer patients and to evaluate their diagnostic performance in predicting malignant IMLN. Materials and Methods: A total of 110 cases with IMLN of BI-RADS category 3 or more, not typical benign IMLN, in MR of breast cancer patients between January 2016 and January 2021 were retrospectively reviewed. After excluding 33 cases, 77 cases were finally included. Among them, 58 and 19 were confirmed as benign and malignant, respectively. Qualitative and quantitative MR imaging features of the IMLN were retrospectively analyzed. Sizes and final assessment categories of IMLN on MRI, mammography, and ultrasound were reviewed. Diagnostic performances of imaging features on MRI, mammography, and ultrasound were then evaluated. Results: For qualitative MR features, shape, margin, and preserved central hilum were significantly different between benign and malignant groups (P < 0.05). For quantitative MR features, long diameter over 6 mm, short diameter over 4 mm, and cortical thickening over 3 mm showed high sensitivities in predicting malignant IMLNs (89.5%, 94.7%, and 100%, respectively). Size exceeding 1 cm showed high specificity and accuracy in predicting malignant IMLN on MR, mammography, and ultrasound (91.4% and 80.5%; 96.6% and 79.25; 98.3% and 80.5%, respectively). Conclusion: Various MR imaging features and size can be helpful for predicting malignant IMLN in breast cancer patients.

• 임상간호연구
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• 제29권1호
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• pp.67-74
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• 2023

Purpose: This study aimed to identify the effect of warm scarf on xerostomia and sore throat in postoperative colon cancer patients. Methods: A total of 40 participants with colon cancer who underwent colon cancer operation over 2hours were included from C University hospital in Seoul. The number of experimental group and control group is each 20 calculated by G*Power, and they were assigned by using nonequivalent control group no-synchronized design. In the experimental group, a warm scarf was applied to the neck for 120 minutes from entering the recovery room after the colorectal cancer surgery was completed. In the experimental group and the control group, xerostomia and sore throat were measured twice at 60-minute intervals. The degree of xerostomia was measured through the degree of wetness of the absorbent paper in mm, and the degree of sore throat was measured through the NRS (Numeral Rating Scale). Data were collected using self-administered questionnaires from August 2018 to September 2020 and were analyzed using IBM SPSS/WIN 21.0 Descriptive statistics, x² test, Fisher's exact test, t-test were used to determine the participant's characteristics. The effect of warm scarf on xerostomia and sore throat were separately estimated by Repeated Measures ANOVA. Results: The experimental group showed significant decrease of xerostomia and sore throat as time goes (p<.001). Conclusion: Results indicate that warm scarf on xerostomia and sore throat in postoperative colon cancer patients is helpful method for relieving side effect of tracheal intubation.

• Smart Structures and Systems
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• 제31권1호
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• pp.57-68
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• 2023

Bridge hangers, such as those in suspension and cable-stayed bridges, suffer from cumulative fatigue damage caused by dynamic loads (e.g., cyclic traffic and wind loads) in their service condition. Thus, the identification of damage to hangers is important in preserving the service life of the bridge structure. This study develops a new method for condition assessment of bridge hangers. The tension force of the bridge and the damages in the element level can be identified using the Bayesian optimization method. To improve the number of observed data, the additional mass method is combined the Bayesian optimization method. Numerical studies are presented to verify the accuracy and efficiency of the proposed method. The influence of different acquisition functions, which include expected improvement (EI), probability-of-improvement (PI), lower confidence bound (LCB), and expected improvement per second (EIPC), on the identification of damage to the bridge hanger is studied. Results show that the errors identified by the EI acquisition function are smaller than those identified by the other acquisition functions. The identification of the damage to the bridge hanger with various types of boundary conditions and different levels of measurement noise are also studied. Results show that both the severity of the damage and the tension force can be identified via the proposed method, thereby verifying the robustness of the proposed method. Compared to the genetic algorithm (GA), particle swarm optimization (PSO), and nonlinear least-square method (NLS), the Bayesian optimization (BO) performs best in identifying the structural damage and tension force.

• Genomics & Informatics
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• 제21권3호
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• pp.29.1-29.9
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• 2023

Preterm birth (PTB), a pregnancy-related disease, is defined as a birth before 37 weeks of gestation. It is a major cause of maternal mortality and morbidity worldwide, and its incidence rate is steadily increasing. Various genetic factors can contribute to the etiology of PTB. Vascular endothelial growth factor A (VEGFA) gene is an important angiogenic gene and its polymorphisms have been reported to be associated with PTB development. Therefore, we conducted a case-control study to evaluate the association between VEGFA rs699947, rs2010963, and rs3025039 polymorphisms and PTB in Korean women. A total of 271 subjects (116 patients with PTB and 155 women at ≥38 weeks of gestation) were analyzed in this study. The genotyping of VEGFA gene polymorphisms was performed using polymerase chain reaction- restriction fragment length polymorphism. No significant association between the patients with PTB and the control groups was confirmed. In the combination analysis, we found a significant association between PTB and VEGFA rs699947 CC-rs2010963 GG-rs3025039 CC combination (odds ratio, 3.77; 95% confidence interval, 1.091 to 13.032; p = 0.031). The VEGFA rs699947, rs2010963, and rs3025039 polymorphisms might have no genetic association with the pathogenesis of PTB in Korean women. However, the combination analysis indicates the possibility that VEGFA acts in PTB pathophysiology. Therefore, larger sample sets and replication studies are required to further elucidate our findings.