• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.1
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• pp.50-63
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• 2021

Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) is an autosomal recessive inherited disorder form of primordial dwarfism, caused by mutations in the pericentrin gene. The purpose of the study was to examine the clinical and radiological features, physicochemical properties and microstructures of the tooth affected with MOPD II. The mandibular 2nd molar was collected from the MOPD II patient. Micro-computerized tomography, scanning electron microscopy, energy dispersive spectrometry and Vickers microhardness analysis were performed on the MOPD II and the normal control. The morphology of the MOPD II tooth appeared to have malformed pulp and root and showed a small size. The mineral density measurement showed that the MOPD II tooth had similar scores in the enamel, but lower scores in the root 1/2 and apical dentin compared to the normal control. The microhardness values were smaller in the cusp enamel, root 1/2 dentin and apical dentin of the MOPD II compared to the normal control. In this study, the dental characteristics and the physicochemical properties of a tooth affected with MOPD II were analyzed to improve understanding of the oral manifestations of the disease and to assist in proper dental treatment by identifying precautions.

• Restorative Dentistry and Endodontics
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• v.44 no.3
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• pp.33.1-33.12
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• 2019

Objectives: To evaluate the influence of the restorative technique on the mechanical response of endodontically-treated upper premolars with mesio-occluso-distal (MOD) cavity. Materials and Methods: Forty-eight premolars received MOD preparation (4 groups, n = 12) with different restorative techniques: glass ionomer cement + composite resin (the GIC group), a metallic post + composite resin (the MP group), a fiberglass post + composite resin (the FGP group), or no endodontic treatment + restoration with composite resin (the CR group). Cusp strain and load-bearing capacity were evaluated. One-way analysis of variance and the Tukey test were used with ${\alpha}=5%$. Finite element analysis (FEA) was used to calculate displacement and tensile stress for the teeth and restorations. Results: MP showed the highest cusp (p = 0.027) deflection ($24.28{\pm}5.09{\mu}m/{\mu}m$), followed by FGP ($20.61{\pm}5.05{\mu}m/{\mu}m$), CR ($17.62{\pm}7.00{\mu}m/{\mu}m$), and GIC ($17.62{\pm}7.00{\mu}m/{\mu}m$). For load-bearing, CR ($38.89{\pm}3.24N$) showed the highest, followed by GIC ($37.51{\pm}6.69N$), FGP ($29.80{\pm}10.03N$), and MP ($18.41{\pm}4.15N$) (p = 0.001) value. FEA showed similar behavior in the restorations in all groups, while MP showed the highest stress concentration in the tooth and post. Conclusions: There is no mechanical advantage in using intraradicular posts for endodontically-treated premolars requiring MOD restoration. Filling the pulp chamber with GIC and restoring the tooth with only CR showed the most promising results for cusp deflection, failure load, and stress distribution.

• Korean Journal of Heritage: History & Science
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• v.46 no.3
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• pp.48-67
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• 2013

This study was focused on the recognition of historical values and the establishment of conservation schemes for a Silla stone monument in Bongpyeong-ri, Uljin by combining the humanistic investigation of inscription reinterpretation and the scientific conservational diagnosis of deterioration. According to the investigation of inscription, a total of 13 letters were reconsidered compared to the preceding researches. Thus, the meaning and interpretation of previous inscription was partially changed. This monument is composed of gneissose leucogranite and the most suitable site as provenance of the stone would be the Jukbyeon seashore (2.1km). The site shows similar color, size and composition of minerals, gneissose structure and magnetic susceptibility as the Bongpyeong stone monument. This monument developed a structural crack (crack index 0.4) and a microcrack (crack index 2.0) along the gneissose structure. The horizontal strength is weaker than the vertical strength. Therefore, the cracks should be reinforced and treated. However, consolidating is not urgently needed because the total weathering grade by ultrasonic velocity shows the stage of moderate weathering(3,403m/s, 0.32). Also, the major problems of chemical deterioration are blackening (85.2%) with soil, iron oxide,rubbing mark, and salt crystals (17.3%) from the sea. Therefore, the contaminants and the salt crystals should be removed using pressure spray and pulp paper, while the application of poultice should be examined through clinical tests.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.15 no.1
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• pp.55-59
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• 2019

Pierre Robin sequence(PRS) is characterized by a triad of clinical signs: micrognathia, glossoptosis and cleft palate. These anatomical deformities of PRS predispose patients to respiratory problems and feeding difficulties at birth. Maintaining oral hygiene and enduring dental treatment are complicated by their general conditions of PRS patients. We present a case of dental treatment of PRS patient under general anesthesia. A 3-year-old boy with PRS visited Seoul National University Dental Hospital for caries treatment. Clinical and radiographic examinations revealed multiple carious lesions. Considering the patient's medical condition and compliance of treatment, dental treatment under general anesthesia was decided. Despite expected challenges of managing the airway of the patient, intubation was performed successfully. The patient was treated with pulp treatments and restorations using composite resin and stainless steel crowns. No complications were observed during and after the procedure.

• Journal of Mushroom
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• v.17 no.3
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• pp.126-131
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• 2019

This study sought to identify the optimum substrate composition for the stable bottle cultivation of Sparassis latifolia. The main substrate was fermented larch sawdust. Six nutrient sources were mixed at a maximum volume ratio of 20%. The fresh weight of fruit body was the highest at 128.5 g for GMSL69033 and 126.6 g for 'Neoul' in the treatments of beet pulp and corn flour in a volume ratio of 15:5. In addition, the total cultivation period was 94 days, which was shorter than that required for other treatments. The selected substrate characteristics were pH 4.7, C:N (carbon to nitrogen) ratio of 106:4, moisture content of 70%, and air filling porosity of 38%. We plan to develop new income items through research on mycelial incubation and fruit body growth conditions.

• Clean Technology
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• v.27 no.2
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• pp.190-197
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• 2021

Kraft lignin is a by-product of the pulp and paper industry, obtained as a black liquor after the extraction of cellulose from wood through the Kraft pulping process. Right now, kraft lignin is utilized as a low-grade boiler fuel to provide heat and power but can be converted into high-calorific biofuels or high-value chemicals once the efficient catalytic depolymerization process is developed. In this work, the multi-functional catalyst of Ru-Mg-Al-oxide, which contains hydrogenation metals, acid, and base sites for the effective depolymerization of kraft lignin are prepared, and its lignin depolymerization efficiency is evaluated. In order to understand the role of different active sites in the lignin depolymerization, the three different catalysts of MgO, Mg-Al-oxide, and Ru-Mg-Al-oxide were synthesized, and their lignin depolymerization activity was compared in terms of the yield and the average molecular weight of bio-oil, as well as the yield of phenolic monomers contained in the bio-oil. Among the catalysts tested, the Ru-Mg-Al-oxide catalyst exhibited the highest yield of bio-oil and phenolic monomers due to the synergy between active sites. Furthermore, in order to maximize the extent of lignin depolymerization over the Ru-Mg-Al-oxide, the effects of reaction conditions (i.e., temperature, time, and catalyst loading amount) on the lignin depolymerization were investigated. Overall, the highest bio-oil yield of 72% and the 3.5 times higher yield of phenolic monomers than that without a catalyst were successfully achieved at 350 ℃ and 10% catalyst loading after 4 h reaction time.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.40-45
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• 2021

Prior studies of physiologically active substances in grapes have focused only on the fruit, pericarp, and branches, as well as the pulp and seeds. The present study assessed the changes in quercetin-3-O-glucuronide (Q3OG) and flavonol glycoside content using grape leaves from Vitis labruscana B. and V. coignetiae at different growth stages and provided basic data for quality control. Content analysis showed that both varieties differed in Q3OG and flavonol glycoside content by growth stage, and the components were found to be high in the order of fruit, maturation, and coloration. Also, Vitis labruscana B. has a better vascular relaxation effect than Vitis coignetiae. These results suggest that in the use of grape leaves as a functional raw material, Q3OG and flavonol glycosides can be used as indicator components. In addition, if raw materials for each growth stage are mixed in a particular ratio, it will be a way to manage the specific efficacy and content of indicator components.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.6
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• pp.367-375
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• 2020

Background: Intraosseous anesthesia (IO) allows the anesthetic solution to be injected directly into the cancellous bone. The anesthetic solution immediately reaches the periapical region, and thus the axonal area of the nerve, where it can temporarily disable the sodium pump. The effect is felt almost without any time delay, and only a small amount of anesthetic solution is required. Methods: This study aims to investigate the efficacy of IO using the AnestoⓇ device after infiltration anesthesia (IA) and/or inferior alveolar nerve block anesthesia (IANB) failed to work in symptomatic irreversible pulpitis (hot tooth). The 33 patients included in the study were treated additionally with 1.7 ml articaine hydrochloride with 1:100,000 epinephrine hydrochloride (UltracainⓇ D-S, Sanofi-Aventis, Frankfurt, Germany) IO. Results: The electrical pulp test showed that 95.76% of the volunteers reacted positively to the combination of IANB or IA with the IO. In women, the additive IO was effective at 97.22%. In men, the IO led to pain elimination in 94.00% of cases. The duration of the IO was less than a quarter of an hour (13.03 min). The IO worked longer in women than in men (13.61 min vs. 12.33 min). Overall, more than every third tooth that needed trepanation was located in the posterior area of the mandible (36.4%). Treatment of hot teeth in this area was associated with an increased pulse rate and increased residual pain. There was a moderate correlation (Spearman-Rho [IRI] = 0.280) between the Visual Analog Scale (VAS) score and bone density, and a significant correlation (IRI = 0.612) between subjective residual pain and bone width. The IO resulted in a moderate, transient increase in the pulse rate by approximately 20 bpm. This is similar to the temporary increase in heart rate after conventional anesthesia techniques in non-preloaded patients and can be considered clinically irrelevant. Conclusion: IO with the AnestoⓇ device as an extension and deepening of local pain elimination is recommended for the treatment of hot teeth.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.708-714
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• 2011

Wood store carbon that the forest absorbed until burned or decomposed over a long period. Such materials are most used in houses except in paper and pulp, and the use of wood in houses play an important role in reducing green-house gases. Therefore, we estimated the amount of carbon stocks in Korean houses, and analyzed how much contribution such stocks offers to green-house gas reduction. As the result, the carbon stocks amount of the wood products in Korean houses was 28.4 million $tCO_2$, which is 4.6% of the total annual green-house gas emission in Korea (620 million $tCO_2$ e), and 77.4% of forest sinks (LULUCF). Even though few wooden houses which use most wood in housing exist in Korea, the carbon stocks of wood products in houses in 2010 increased to 4.1 times that in 1975 (21.4 million $tCO_2$) because the carbon stocks increased due to apartment construction, which hit its stride from the last 1980's.

• Clean Technology
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• v.26 no.4
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• pp.270-278
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• 2020

Palladium (Pd) has been widely used in various industrial applications such as jewelry, catalyst, and dental materials despite its limited resources. It has been gaining attention to recover Pd with high purity from the spent materials. This study investigated the optimum conditions for the leaching and recovery of metallic Pd. The leaching parameters are HCl concentration, temperature, time, concentration of oxidants, and pulp density. 97.2% of Pd leaching efficiency was obtained in 3 M HCl with 3 vol% oxidants at 80℃ for 60 min. The ratio of hydrogen peroxide to sodium hypochlorite played a critical role in the leaching efficiency due to the supply of Cl- ions in the leachate. Moreover, the complete recovery of Pd in the leachate was achieved at 80℃ with 0.3 formic acid/leachate after adjusting the pH value of 7. This situation was ascribed to the decomposition of formic acid into hydrogen gas and carbon dioxide at 80℃. ICP-AES and XRD characterized the recovered Pd powder, and the purity of the recovered powder was found to be 99.6%. Consequently, the recovered Pd powder with high purity could be used in circuits, catalyst precursors, and surgical instruments.