• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.350-355
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• 2009

Bond strength depends on characteristics of bonding surface and restorative technique. The majority of studies dealing with dentin bond strength were carried out on flat bonding surface, therefore, difference of bond strength between axial wall and pulpal wall is not clear yet. This study evaluated bonding difference between cavity walls in class I composite resin restoration with different filling techniques. Twenty extracted caries-free human third molars were used. Cavities were prepared in 6 ${\times}$4 ${\times}$3 mm box-type and divided into four groups according to filling technique and bonding surface: Group I; bulk filling - pulpal wall, Group II; bulk filling - axial wall, Group III; incremental filling - pulpal wall, Group IV; incremental filling - axial wall. Cavities were filled with Filtek $Z250^{(R)}$(3M/ESPE., USA) and Clearfill SE $bond^{(R)}$(Kuraray, Japan). After 24 hour-storage in $37^{\circ}C$water, the resin bonded teeth were sectioned bucco-lingualy at the center of cavity. Specimens were vertically sectioned into 1.0 ${\times}$1.0 mm thick serial sticks perpendicular to the bond surface using a low-speed diamond saw (Accutom 50, Struers, Copenhagen, Denmark) under water cooling. The trimmed specimens were then attached to the testing device and in turn, was placed in a universal testing machine (EZ test, Shimadzu Co., Kyoto, Japan) for micro-tensile testing at a cross-head speed of 1 mm/min. The results obtained were statistically analyzed using 2-way ANOVA and t-test at a significance level of 95%. The results were as follows: 1. There was no significant difference between bulk filling and incremental filling. 2. There was no significant difference between pulpal wall and axial wall, either. Within the limit of this study, it was concluded that microtensile bond strength was not affected by the filling technique and the site of cavity walls.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.333-339
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• 2009

This study was done to determine if there is any difference in microleakage between experimental composite resins, in which various proportions of three component photoinitiators (Camphoroquinone, OPPI, Amine) were included. Four kinds of experimental composite resin were made by mixing 3.2% silanated barium glass (78 wt.%, average size; 1 ${\mu}m$) with each monomer system including variously proportioned photoinitiator systems used for photoinitiating BisGMA/BisEMA/TEGDMA monomer blend (37.5:37.5:25 wt.%). The weight percentage of each component were as follows (in sequence Camphoroquinone, OPPI, Amine): Group A - 0.5%, 0%, 1% / Group B - 2%, 0.2%, 2% / Group C - 0.2%, 1%, 0.2% / Group D - 1%, 1%, 2%. Each composite resin was used as a filling material for round class V cavities (diameter: 2/3 of mesiodistal width; depth: 1.5 mm) made on extracted human premolars and they were polymerized using curing light unit (XL 2500, 3M ESPE) for 40 s with an intensity of 600 mW/$cm^2$. Teeth were thermocycled fivehundred times between $50^{\circ}C$and $550^{\circ}C$for 30s at each temperature. Electrical conductivity (${\mu}A$) was recorded two times (just after thermocycling and after three-month storage in saline solution) by electrochemical method. Microleakage scores of each group according to evaluation time were as follows [Group: at first record / at second record; unit (${\mu}A$)]: A: 3.80 (0.69) / 13.22 (4.48), B: 3.42 (1.33) / 18.84 (5.53), C: 4.18 (2.55) / 28.08 (7.75), D: 4.12 (1.86) / 7.41 (3.41). Just after thermocycling, there was no difference in microleakage between groups, however, group C showed the largest score after three-month storage. Although there seems to be no difference in microleakage between groups just after thermocycling, composite resin with highly concentrated initiation system or classical design (Camphoroquinone and Amine system) would be more desirable for minimizing microleakage after three-month storage.

• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.197-205
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• 2009

The purpose of this study was to investigate the treatment pattern of patients with neuropathic pain (NeP) in Korea through computerized database of Health Insurance Review and Assessment Service (HIRAS) over three years' period from 2003 to 2005. The results showed that the numbers of treatment visits were the highest for diabetic neuropathy (DN), followed by postherpetic neuralgia (PHN) and trigeminal neuralgia (TN) in order. Top 3 specialties for treatment visits due to NeP conditions were neurology, neurosurgery and anesthesiology. While cost of a treatment visit was higher in anesthesiology and emergency clinics compared to other clinics, there was a tendency to increase costs for visits to clinics of rehabilitation medicine and family medicine over the three years. Cost of dental visits was relatively high for TN, atypical facial pain (AFP) and atypical odontalgia (AO). Surgeries frequently applied to patients with NeP were sympathetic plexus or ganglion block, block of peripheral branch of spinal nerve and cranial nerve or its peripheral branch block. Most common prescribed medication were anticonvulsants, anti-inflammatory analgesics and anti-psychotic drugs while anti-inflammatory analgesics were overwhelmingly frequently prescribed for AO and glossodynia. Based on the results of this study, NeP disorders more relevant to dentists were AO, TN and AFP, TN of which seems to be the most important in terms of patients' number and cost for treatment visits. This indicates that dentists, especially oral medicine specialists should actively participate in management of TN, AO and AFP and share relevant information with patients and community.

• Journal of Yeungnam Medical Science
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• v.22 no.2
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• pp.166-182
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• 2005

Background: Cyclin-dependent kinase (CDK) inhibitors are family of molecules that regulate the cell cycle. The CDKN2, a CDK4 inhibitor, also called p16, has been implicated in human tumorigenesis. The CDKN2 inhibits the cyclin/CDK complexes which regulate the transition from G1 to S phase of cell cycle. There is a previous report that homozygous deletion of CDKN2 region on chromosome 9p21 was detected frequently in astrocytoma, glioma and osteosarcoma, less frequently in lung cancer, leukemia and ovarian cancer, but not detected in colon cancer and neuroblastoma. However, little is known about the relationship between CDKN2 and laryngeal cancer. Therefore this study was initiated to investigate the role of CDKN2 in human laryngeal squamous cell carcinoma development.1) Materials and methods: We used 5 human laryngeal carcinoma cell lines whether they have deletions or losses of CDKN2 gene expression by DNA-PCR or RT-PCR, respectively. We examined 8 fresh frozen human laryngeal cancer tissues to detect the loss of heterozygosity (LOH) of CDKN2. PCR was performed by using microsatellite markers of short arm of human chromosome 9 (D9S126, D9S144, D9S156, D9S161, D9S162, D9S166, D9S171, D9S200 and D9SIFNA). For informative cases, allelic loss was scored if the signal of one allele was significantly decreased in tumor DNA when compared to the same allele in normal DNA. Results: The CDKN2 DNA deletion was observed in 3 cell lines. The CDKN2 mRNA expression was observed in only one cell line, which was very weak. LOH was detected in 7 cases (87.5%). Conclusion: These results suggest that CDKN2 plays a role in the carcinogenesis of human laryngeal squamous cell carcinoma.

• Journal of the Geological Society of Korea
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• v.54 no.5
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• pp.477-488
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• 2018

Fluid muds commonly occur in estuarine environments, but their ancient examples have rarely been studied in terms of depositional characteristics and processes. Cores of estuarine channel deposits of the Early Cretaceous McMurray Formation, Alberta, Canada show various mudstone layers that possess depositional characteristics of high clay-concentration flows. These mudstone layers are examined in detail through microscopic observation of thin sections and classified into three microfacies (<1 to 25 mm thick) on the basis of sedimentary texture and structures. Structureless mudstone (Microfacies 1) consists mainly of clay particles and contains randomly dispersed coarser grains (coarse silt to fine sand). This microfacies is interpreted as being deposited by cohesive mud flows, i.e., fluid muds, which possessed sufficient strength to support suspended coarser grains (quasi-laminar plug flow). Silt-streaked mudstone (Microfacies 2) mainly comprises mudstone with dispersed coarse grains and includes very thin, discontinuous silt streaks of coarse-silt to very-fine-sand grains. The texture similar to Microfacies 1 indicates that Microfacies 2 was also deposited by cohesive fluid muds. The silt streaks are, however, suggestive of the presence of intermittent weak turbulence under the plug (upper transitional plug flow). Heterolithic laminated mudstone (Microfacies 3) is characterized by alternation of relatively thick silt laminae and much thinner clay laminae. It is either parallel-laminated or low-angle cross-laminated, occasionally showing low-amplitude ripple forms. The heterolithic laminae are interpreted as the results of shear sorting in the basal turbulent zone under a cohesive plug. They may represent low-amplitude bed-waves formed under lower transitional plug flows. These three microfacies reflect a range of flow phases of fluid muds, which change with flow velocities and suspended mud concentrations. The results of this study provide important knowledge to recognize fluid-mud deposits in ancient sequences and to better understand depositional processes of mudstones.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1976.06a
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• pp.88.1-88
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• 1976

The authors have been performed a statistical survey for 228 cases with foreign bodies in the food and air passages who had visited the department of Otolaryngology, National Medical Center and removed endoscopically during the period of last 10 years from 1966 to 1975. The following results were obtained: 1. The total numbers of foreign bodies in the food and the air passages were 228 cases, and among of them 181 cases were foreign bodies in the food passage and 47 cases were foreign bodies in the air passage. The ratio between the food and the air passages was about 3.7 : 1. 2. The prevalent foreign bodies in the esophagus were coin, meat and food particles and bone in order of frequency. In air passage, bean and peanut were most prevalent foreign bodies and the next were metalic substances, fish bone in order of frequency. 3. In the age incidence, 65.4% of the esophageal foreign bodies and 67.6% of foreign bodies in the air passage were under 5 years of age especially coin, 92.9%. 4. In sex distribution, 99 cases were female, and the ratio between male and female was 1.3:1. There was no significant difference between male and female in the foreign bodies of the esophagus but the foreign bodies in the air passage were more prevalent in male as the ratio of 2.1:1. 5. The most prevalent site of lodgement in esophagus was first physiologic narrowing of the esophagus as the count of 83.8%. In foreign bodies of the air passage, bronchial foreign bodies were most frequent. And bronchial foreign bodies were more frequent in the right side as the ratio of 3.7:1. 6. In duration of lodgement, 56.0% of foreign bodies of the food passage were removed within 24 hours and almost of them were removed within 5 days. In foreign bodies in the air passage, only 32.4% were removed within 24 hours but 29.7% were removed within more than 1 week in the air passage. 7. Under the esophagoscope, granulation tissue were noted in the 5 cases of the foreign bodies in the esophagus due to foreign bodies. In foreign bodies of the air passage, complication were encountered in the 4 cases and also removed surgically and among of them, 2 patients were expired due to complications during post operative course.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.10-14
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• 1978

There are relatively many reports have been issued on he active movement of cuticle of larva. which tend to protect their body, however, only a few reports have been disclosed on the cuticle of pupal body except the small portion of rectangle which shown tortoise-shell shape. In this connection, many portion of the external structure of pupal cuticle has been studied and the following. results were found: 1) No. spot of rectangle which is sculptured in the surface of cuticle that born by branching. out of the development of cell in imaginal bud of antenna and head were found. However, in the compound eye of net shaped sculpture was found in the (equation omitted) shaped parts which holding. the diameter of about 8u and the surrounding area has the small bump and the one is dark brown coloured comparing with shape. 2) The sculpture shape of thorax is a little different than in the head. However, (equation omitted) portion is varies from the segment to segment. In general, it is not very clear than the compound eye in the head, the dark brown bump shape is slowly fade a from the prothorax, mesothorax to metathorax. 3) The surface of intersegment membrane is colourless or slightly yellow, and the entire surface has stripped marking with thine lines. 4) In the abdominal segment, there are many and small sculptures in net shape around the (equation omitted) shape portions. 5) The size of sculpture in (equation omitted) portion of abdomen is smaller than one in thorax, and in the same segment, the dorsal is smaller than abdomen and the rear portion of the segment is larger than the front of segment. 6) After the 7th abdominal segment, no intersegmental membrane is found and the cuticle of the external structure is the same as external structure of the segment. 7) The seta is not found in head, compound eye, antenna and wing which portions were subdivided by development of imagined bud of the cell, no seta is found in cuticle of the segment in the general cell of the larva stage and also in the dorsal and intersegmental membrane.

• The Journal of Korean Academy of Sensory Integration
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• v.19 no.2
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• pp.12-25
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• 2021

Objective : This study explored the effects of family-centered coaching using a sensory integration-based approach on the levels of performance and satisfaction for children with autism spectrum disorder (ASD). Methods : From April 16, 2020 to August 6, 2020, participants included 10 children with ASD, between the ages of three to six who met the inclusion criteria, and their guardians. I used the Canadian Occupational Performance Measure (COPM) to evaluate the children's levels of performance and satisfaction and the Goal Attainment Scaling (GAS) to evaluate their occupational performance. The experimental group (n=5) continued the sensory integration therapy while receiving their personalized family-centered coaching training for 60 minutes per week. This continued for four weeks via home visits and video calls. The control group (n=5) also continued to receive the sensory integration therapy while receiving sensory integration-based general counseling in relation to activity objectives. Results : Statistically significant differences were found in the scores of COPM performance and satisfaction and the GAS scores between the experimental group and the control group, before and after the intervention (p<.05). Statistically significant differences were found in score changes in COPM and GAS, between the two groups (p<.05). Cohen's d also showed a big effect size on the scores of COPM satisfaction (d=2.768) and the GAS scores (d=2.786). Conclusion : This study demonstrated that the sensory integration-based, family-centered coaching had more positive effects on the level of performance and satisfaction of children with ASD, than general counseling.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.789-797
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• 2021

The worldwide sizes of container ships are rapidly increasing. The container ship size in 2005, which was about 9,200 TEU has increased to 24,000 TEU in recent times. In addition to the increase in the sizes of the container ships, the arrivals/departures of large container vessels to/from Korea have also increased. Hence, the necessity for reviewing safe passage of such vessels is emphasized. In the present study, a 24,000 TEU container vessel was used as a model ship to calculate the under-keel clearance (UKC) at Gadeok Channel through which vessels must pass to arrive at Busan New Port, in accordance with the Korean Port and Fishing Port Design Standards and Commentary. In addition, the maximum allowable speed that meets UKC standards was calculated using various squat formulas, whose results were then compared with the current speed limit standards. The analysis results show that Busan New Port requires 10% marginal water depth, and the squat that meets this requirement is 0.95 m. Gadeok Channel requires 15% marginal water depth, and the squat that meets this requirement is 1.78 m; in this case, the maximum allowable speed is calculated as 15 kts. Busan New Port has set the speed limit as 12 kts, which is higher than the calculated 11 kts. Thus, speed limit reconsideration is required in terms of safety. However, the set speed limit for Gadeok Channel is 12 kts, which is lower than the calculated 15 kts. Thus, additional considerations may be provided to increase the speed limits for smooth navigational passage of vessels. The present study, however, is constrained by the fact that it reflects only a limited number of elements in the UKC and allowable speed calculations; therefore, more accurate UKC and safe speed values can be suggested based on extended studies to this research.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.81-88
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• 2018

This study analyzed the characteristics of 6 recyclable bulking agents which can replace sawdust and rice hulls that are commonly used in livestock manure composting. The content of all the hazardous chemicals found in the bulking agents used in this experiment was between 0.0 and 34.1 ppm, which was noticeably lesser than the maximum content levels of hazardous substances 5.0~900.0 ppm prescribed by the Rural Development Administration(RDA), which means that the bulking agents would be able to replace sawdusts and rice husks. The water content of the bulking agents ranged from a minimum of 12.4% to a maximum of 16.6% in the original state, which was much less than 60%, the optimal moisture content. These results indicate that they would be able to function fully as bulking agents. Their water absorption rate was in the range of minimum 31.9% ~ maximum 600.0%, which showed huge differences among the types of bulking agents. The most appropriate bulking agent in terms of water absorption rate was wood pellets. It was the highest in the wood briquette manufactured by A, which was followed by C and B in the order. The shear strength of the 5 types of bulking agents in the original state was 271.7 N on an average, the highest figure of all, except for the oak briquette whose shear strength could not be measured and the wood pellets in the absorption state. The shear strength in the dry and absorption states then followed, and were 78.0 N and 27.7 N on an average, respectively. The wood briquette of A recorded considerably lower shear strength than that of B and C. Overall, shear strength tended to increase according to lower water absorption rates. Since pine wood chips and oak cuts have relatively greater shear strength even in the absorbing state than the other materials, they will be able to endure some power in the case of stirring with pig droppings.