• The Journal of Korean Academy of Prosthodontics
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• v.34 no.4
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• pp.746-754
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• 1996

The purpose of this study was to evaluate the fracture strength of porcelain laminate veneer with various lingual extention length when incisal restoring. Sixty recently extracted, intact maxillary incisors were used and stored in a physiologic saline solution from the time of extraction. Seating form was preparation at the labial surface of each tooth with a water-cooled round diamond bur. Standard block was formed with 32 gauge and 24 gauge wax at tooth labial and lingual surface. Lingual extention length differed according to each group. (group I : 0.5mm, group II : 1 mm, group III : 2mm, group IV : 0mm) All tooth specimens were impressioned with examix(GC Inc., Japan). Refractory cast were maked with refractory die material(Ceramco Inc., U.S.A.) Laminate porcelain (Ceramco II Veneer porcelain, Ceramco Inc., U.S.A.) was condensed in refractory die cast and baked according to the manufacturer's recommendations. Each surface was contoured with low speed diamond bur according to guide block. All porcelain specimens were sandblasted and ultrasonically cleaned in distlled water for 3 minutes. Then, all porcelain specimen were etched with 8% hydrofluoric acid for 5 minutes. Sixty specimens were bonded with composite resin cement(Choice Porcelain Veneer System, Bisco Inc., U.S.A.) according to manufacture's directions. The fracture loads of the specimen were measured by Instron universal testing machine. The mean values of fracture loads for the groups were statistically compared by Duncan's multiful range test. The result were as follows : Mean fracture strengths of each group were 86.95Mpa in no lingual extention group, 44.98Mpa in 0.5mm lingual extention group, 27.47Mpa in 1mm lingual extention group, 19.61Mpa in 2mm lingual extention group. There was a statistically significant difference between all group(p<0.01).

• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.282-289
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• 2014

After being laminated with a combination of glass fiber reinforced plastic and plywood, the GFRP laminated plate was densificated for 1 hour at $150^{\circ}C$ with pressure of $1.96N/mm^2$. A partial reinforced beam was produced by attaching the 5 GFRP laminated plates to the joint of glulam and the column. In addition, the column to beam joint was produced by using reinforced laminated wooden pin which was made of GFRP sheet and plywood, fiber glass reinforced cylindrical-LVL column. The joint was made of round log, glulam and drift pin as the reference specimen, and its moment resistance was evaluated. As a result, the strength performance of specimens with partial reinforced beams were 1.8 times stronger than the reference specimen on average. Furthermore, rupture was neither occurred on partial reinforced beam nor column. Toughness and stiffness of joints were also fine. The GFRP sheet reinforced laminated plate showed better reinforcement effect than GFRP textile reinforced one. GFRP sheet was inserted into each layer of laminate, and it showed good condition in rotation-angle and strength, therefore it is the most appropriate to reinforce the part of the beam.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.235-238
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• 2014

One specimen (619.0 mm in standard length) of Tentoriceps cristatus, belonging to the family Trichiuridae, was newly collected in the coastal waters of Jeju Island by the bottom trawl. This species was characterized by the following morphological traits: round dorsal profile of head (vs. straight for the similar species, Eupleurogrammus muticus); pelvic fin locating below the 12th dorsal fin ray (vs. 15th~17th); V, 131 dorsal fin rays; 11 pectoral fin rays; 1 pelvic fin ray changed to be a scale-like process; II anal fin rays (second one is changed to be a scale-like process). We suggest the Korean names, "Tu-gu-gal-chi-sok" and "Tu-gu-gal-chi" for the genus and species, respectively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.6
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• pp.653-656
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• 2008

Mesenchymal chondrosarcoma is a rare malignant tumor of bone and soft tissue. This aggressive form of chondrosarcoma represents only 3% to 9% of all chondrosarcomas. This neoplasm is characterized by sheets or clusters of undifferentiated spindle or round cells surrounding discrete nodules of well-differentiated cartilage. We experienced a case of mesenchymal chondrosarcoma on mandibular body. Two years ago, the patient had been treated the intrabony cystic lesion on mandiblular left body. At that time, cartilage portion was not detected in the cystic specimen. Two years after cyst enucleation, the recurred large neoplasm in the mandibular left body was noted, and it was diagnosed as 4.5 cm sized mesenchymal chondrosarcoma. The mandibular tumor was widely resected and rigid-plate and cervical musculocutaneous flap were used for reconstruction of resected bone and soft tissues. No complications and recurrence were noted for 6 months postoperatively.

• The Journal of the Korean dental association
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• v.58 no.11
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• pp.683-689
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• 2020

Dentin surface of non-carious lesion is usually attached with oral biofilm. The biofilm should be removed before application of restorative material, because it may reduce the bond strength of adhesive system. The aim of this study was to evaluate the microtensile bond strength, when the biofilm was removed with brush or bur. Twenty extracted human third molars were sectioned horizontally to obtain dentin surface. Specimen were divided randomly into four group. Biofilm formation was performed in three group, except for Group 1 (negative control). Biofilm was removed as follows: Group 3, using ICB brush; Group 4, using lowspeed round bur #2. Group 2 (positive control) was not removed Biofilm. And in all four groups, the adhesive system (Optibond FL, Kerr) was applied to etched dentin surface, and resin composite was built up in three 1mm increments. After 24 hour storage in distilled water, the teeth were perpendicularly sectioned to obtain beams (1 × 1 mm2). Microtensile bond strength was measured and the data were statistically analyzed using one-way ANOVA and Tukey's post hoc test (p<0.05). Group 4 showed the highest microtensile bond strength (p<0.05), Group 3 showed no significant improvements when compared to Group 1. Group 2 showed lowest microtensile bond strength (p<0.05). When restoring a non-carious cervical lesion, it is essential to remove the biofilm present on the dentin surface. In addition, in the method of removing the biofilm, both the brush removal method and the bur removal method were effective.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.3
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• pp.34-41
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• 1990

The pilomatricoma (calcifying epithelioma of Malherbe) is rare benign hard, spherical and freely movable cutaneous tumor, which was differentiated from hair cells, particulary hair cortex cells. It is usually occured as a single, asymptomatic, 0.5 cm to 3.0 cm sized, deep seated, firm nodule, covered by normal or pink skin. It arises chiefly in young people, including children, and most often in the head, neck and upper extrimites. The authers experienced a case of pilomatricoma which occured in preauricular region. This case was summarized as follows. 1. 10 years old female has suffered from hard subepidermal mass on preauricular area and she visited our out patient clinic. So we performed surgical extirpation and the excised specimen was pathologically examined. 2. Grossly the tumor measures 2.0 cm in diameter and firm, bosselated, spherical shaped which covered by a thin layer of fibrous tissue. On cut section, it shows spicular gritty surfaces, well encapsulation, interwoven and keratotic lamellae. 3. Histopathologically, the epithelial masses of the tumor are composed of two type of cells, basophilic cells and shodow cells. The basophilic cells resemble hair matrix cells which posses round or elogated, deeply basophilic nuclei and scanty cytoplasm. The shadow cells show a central, unstained shadow at the site of the lost nucleus. Gradual development of basophilic cells into shadow cells can be observed. Foci of calcification are present within the lobule of shadow cells. The stroma of the tumor shows a considerable foreign body giant cell reaction adjacent to the shadow cells. 4. No recurrence was observed until post-operative 40 months.

• Tuberculosis and Respiratory Diseases
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• v.58 no.2
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• pp.179-184
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• 2005

Epithelioid hemangioendothelioma (EH) is a rare borderline malignant tumor which originating from vascular endothelial cells and occurs in many organs such as soft tissues, lung, liver and bone. But, pulmonary EH which simultaneously involves pleura and liver is very rare. In the present report, we describe an uncommon case of EH involving the lung, pleura and liver in a 26-year-old woman. Chest CT showed single nodule in right upper lobe with large amount of pleural effusion at ipsilateral side and abdominal CT multiple round low densities in liver. The EH was confirmed by microscopic analysis and immunohistochemical staining of CD34+ from open lung biopsy specimen.

• The Korean Journal of Cytopathology
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• v.7 no.2
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• pp.192-196
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• 1996

The principal significance of the urothelial changes caused by polyomavirus activation is in an erroneous diagnosis of urothelial cancer; however, the clue to their benign nature is the smooth structureless nuclear configuration and the relative paucity of affected cells. Though virologic studies and electron microscopy are usually needed to firmly establish the diagnosis, cytology is the most readily available and rapid means of establishing a presumptive diagnosis of human polyomavirus infection. A urine specimen of a 24-year-old man with hemorrhagic cystitis beginning two months after bone marrow transplantation for acute myeloblastic leukemia(M2) was submitted for cytologic evaluation. Cytologic findings revealed a few inclusion-bearing epithelial cells intermingled with erythrocytes, neutrophils, lymphocytes, and macrophages. Most of the inclusion-bearing fells had large, round to ovoid nuclei almost completely filled with homogeneous dark, basophilic inclusion. The chromatin was clumped along the periphery and the cytoplasm was mostly degenerated. The other cells exhibited irregular inclusions attached to the nuclear membrane surrounded by an indistinct halo. These findings were consistent with polyomavirus infection.

• The Korean Journal of Cytopathology
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• v.12 no.2
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• pp.121-125
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• 2001

Primary small cell carcinoma of the urinary bladder is a rare malignant tumor. A more rapidly fatal course may be seen in advanced stages of small cell carcinoma as compared to similar stages of urothelial carcinoma. It is very important to recognize this distinct form of bladder cancer by urinary cytology The differential diagnosis of small cell carcinoma of the urinary bladder includes metastatic small cell carcinoma, urothelial carcinoma, and primary or secondary malignant lymphoma. This article highlights the urinary cytologic diagnosis of a case of primary small cell carcinoma. A 59-year-old male presented with gross hematuria for five months. Urinary cytology showed high cellularity consisting of tiny monotonous tumor cells in the necrotic background. The tumor cells occurred predominantly singly, but a few in clusters. The cytoplasm was so scanty that only a very narrow rim of it was seen. The nuclei were oval or round and had finely stippled chromatin. Rarely, the nuclei contain visible nucleoli. Frequently cell molding was noted in clusters. Many single cells demonstrated nuclear pyknosis or karyorrhexis. The histologic findings of transurethral resection and partial cystectomy specimen were those of small cell carcinoma. Cytologic distinction may be very difficult but careful attention to clinical features and cellualr details can classify these neoplasms correctly.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.1
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• pp.21-26
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• 2012

Microstructural and mechanical property were evaluated at the medium-sized HT9 (12Cr-1MoWV) forged steel which was considered as primary candidate for the fuel cladding in sodium-cooled fast reactor (SFR). Material was forged at $1170^{\circ}C$ after the induction melting to make round bar as 160mm diameter, 7000mm length then the radial distribution of microstructure as well as microhardness was evaluated. The results showed that overall microstructure exhibited as ferrite-martensite structure, where small amount (2~3%) of delta ferrite was formed throughout the specimen and maximum 15% of transformed ferrite was formed at the center, where it gradually decreased toward the radial direction. Sensitivity analysis of the cooling curve and Time-Temperature-Transformation (TTT) diagram revealed that formation of transformed ferrite could be avoided when the diameter was decreased down to 120mm.