• The Journal of Korean Academy of Prosthodontics
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• v.58 no.2
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• pp.77-85
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• 2020

Purpose: The aim of the present study was to investigate the effects of N-acetyl cysteine (NAC) loading on the bone formation surrounding sandblasted, large-grit and acid-etched (SLA) implants. Materials and methods: Implantation of NAC loaded SLA implants (NSI group) and SLA implants (SI group) was performed bilaterally in the mandible of 4 adult beagle dogs (each group, n = 8). The animals were sacrificed after a healing period of 3 and 6 weeks, respectively (n = 2 animal each). Dissected blocks were processed for histomorphometrical analysis. Bone to implant contact percentage (BIC%) and bone volume (BV%) were assessed histomorphometrically. Results: BIC% of NAC loaded SLA implants were about 50% higher than that of SLA implants at 3 weeks of bone healing, but not significantly (51.79 vs 35.43%; P=.185). BV% of NAC loaded SLA implants were significantly higher than that of SLA implants at 3 weeks of bone healing (45.09 vs 37.57 %; P=.044). At 6 weeks of bone healing, BIC% and BV% of two experimental groups were similar (P>.05). Conclusion: Within the limits of the present study, NAC loading have a positive effects on the early bone formation surrounding SLA implants. So, it might be concluded that NAC loading enhance the osseointegration and shorten the healing time after implantation of the SLA implants.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.653-657
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• 2007

A 12-year-old, intact female Toy Poodle and a 10-year-old, intact male Yorkshire terrier were referred with bilateral mandibular fractures, severe periodontal disease and teeth loss. In the second case, mandibular fractures were repaired with periodontal disease treatment. After a fallow-up period of 1 year, fracture healing was successful in the second case, however in the first case, bone healing was not satisfactory because mandibular fractures were repaired without the treatment of diseased teeth within the fracture line. Nonunion and inflammation of fracture sites, oral malodor confirmed in the first case and normal union of fracture sites observed in the second case. It suggests that the treatment of diseased teeth within the fracture line is mandatory for successful fracture healing.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.376-385
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• 1991

For manufacturing trimming-free plates which have rectangular shaped edges and straight edges in as-rolled state, it is necessary to investigate rolling characteristics of overlap, bulge and width deviation etc. in a standardized plate rolling process. The present wok is for preventing edge overlap as the first approach to develop trimming-free plate rolling technique. An experimental study on overlap control was done with plasticine material in order to examine influence factors and find a control method by use of a laboratory mill scaled down to one tenth of actual production mill. It was found that edge overlapping was increased with the increase of slab thickness and of broadside rolling ratio, but decreased with the increase of chamfered amount on slab edges. In the simulated rolling experiment with edge chamfered slabs of various chamfered angles, the chamfered angle of 60.deg. was the most effective one for reducing overlapping irrespective of slab thickness and of broadside rolling ratio.

• Composites Research
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• v.14 no.3
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• pp.51-56
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• 2001

It is known that the elastic modulus, maximum stress, and maximum strain of fiber-reinforced polymer composites are affected by high pressure. Fracture behavior is also known to be affected by high pressure. In this work, the pressure effect on the compressive fracture toughness of thick quasi-isotropic composites was investigated. Dog-bone type specimens of stacking sequence, [0$^{\circ}$/$\pm$45$^{\circ}$/90$^{\circ}$]$_{11s}$ were used. Compressive fracture tests were conducted under four pressure levels. The pressure levels applied were 0.1 MPa, 100 MPa, 200 MPa, and 300 MPa. Fracture toughness for each pressure level was determined from the compliance method. The results show that the compressive fracture toughness increases with increasing pressure. Specifically, fracture toughness increases 44% as the pressure increases from 0.1 MPa to 300 MPa.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.976-984
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• 2006

Time-temperature superposition has been studied to determine the long-term fatigue life over millions of cycles for glassy polymers. π le superposition is supposed to make an accelerated lifetime testing (ALT) technique possible. Dog-bone shaped specimens made of carbon filled Polycarbonate (PC) were tested under fatigue, based on the stress-lifetime approach (S-N curve). Fatigue-induced localized yield-like deformation is considered as the defect leading to fatigue and its evolution behavior is characterized by a modified energy activation model in which temperature is considered as fatigue acceleration factor. This model allows the reduced time concept to account for effects of different temperature in short-term fatigue data to determine long-term fatigue life through the use of time-temperature superposition that is applicable under a low frequency and isothermal conditions. The experimental results validated that the proposed technique could be a possible method for accelerated lifetime testing (ALT) of time-dependent polymeric materials.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.7 s.166
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• pp.1196-1204
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• 1999

adaption of the model predictions is highly desirable. In general, the width deviation at the head and tail ends of strip may be different from that of the steady state region. Therefore, the dynamic edger corrections can be used to compensate the width deviations which would otherwise occur. For the precise width control, the effect of edger roll gap and rolling conditions on the width deviation of head and tail ends of strip has been investigated and the effective method to decrease width deviation has been proposed. On-line application of dynamic edger control method in this study shows about 50% width compensation at the head end of the strip, and near perfect compensation at the tail end of strip.

• Transactions of Materials Processing
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• v.25 no.2
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• pp.102-108
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• 2016

The aim of the current study was to develop an advanced prediction model for the slab width spread during hot rough rolling. Rough rolling consists of both vertical rolling using a set of profiled edger rolls and horizontal rolling using a set of plain work rolls. FE-simulations were performed to investigate the influences of process variables such as initial slab width, initial thickness, sizing draft, edger roll draft and work roll draft on the final slab width variation. From a statistical analysis of the simulation results, an advanced model, which can predict the slab width spread during the edger rolling and horizontal rolling, was developed. The experimental hot rolling trials showed that the newly developed model provided fairly accurate predictions on the slab width spread during hot rough rolling process using a profiled edger rolls.

• Journal of Veterinary Clinics
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• v.9 no.2
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• pp.457-466
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• 1992

An 11 years old Irish Setter bitch was euthanlzed and necropsied because of clinical findings such as severe purulent nasal discharge and formation of large tumor mass, 8 ${\times}$8cm in size, in the abdominal cavity. A complete unilateral mastectomy had been carried out twice 14 and 22 months before necropsy. The surgically removed masess of the mammary glands had been diagnosed as malignant mixed tumor in each time. Grossly, tumor masses were observed in nasal cavity, infralumbar lymph node, lung, abdominal cavityn and brain. Microscopic findings of the surgically removed masses consisted of tumor epithelial cells, tumor hyaline cartilage-like structures and abundant connective tissues. The mass of the lymph node had similar microscopic features to those of the original malignant mixed tumor of the mammary glands. The tumor osseous tissue and osteoid were observed in the abdominal cavity, lung, and brain. Myoepithelial cells were frequently found on association with the metastatic tumors. From the results, it was concluded that malignant mixed tumor of the mammary glands metastasized to the infralunbar lymph node, abdominal cavity, lung and brain. In addition, the observation in this study supported two theories at the same time that the bone in malignant mixed tumor arises by endochondral ossification of the cartilage formed by the myoepithelial cells and arises by intramembranous ossification of stromal connective tissue or transformed myeopithelial cells. Solid carcinoma of the nasal epielia and granulosa cell tumor were also diagnosed in a mass of the nasal cavity and of the ovaries respectively.

• Journal of Veterinary Clinics
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• v.32 no.1
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• pp.49-55
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• 2015

This study was retrospectively investigated the clinical features, diagnostic imaging, treatment, and prognosis of foreign bodies according to alimentary site and type of foreign body, in 143 dogs. Among 28 breeds, Maltese, Shih Tzu, and terriers including the Yorkshire terrier were presented with high prevalence. Bone was the most commonly identified (33%) foreign body regardless of alimentary site. Approximately 76% of foreign bodies were in the stomach and small intestine. All esophageal foreign bodies were diagnosed on survey radiography, with the most common location being the caudal thoracic esophageal segment. Further diagnostic examinations including ultrasonography or contrast studies were additionally performed to detect radiolucent foreign bodies and perforation or leakage in the stomach and intestine. However, most seeds could be identified based on the characteristic features such as hyperdense thin double lines and inner gas on survey radiography. In conclusion, complications such as peritonitis and intestinal perforation were mainly observed in cases with seeds and linear foreign bodies. Especially, fabric foreign bodies could be induce peritonitis and re-perforation with high prevalence after surgical correction.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.57-57
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• 2003

Canine osteosarcoma is the most common bone tumor in dog and is characterized by locally aggressive and highly metastatic behavior [1]. Generally malignant tumors meta stasizes by hematogenious routes and rarely through lymphatic pathway, and the lymph node is uncommon metastatic site [2,3]. In this case, the patient has a typical osteosarcoma on his proximal humerus that is the common form of canine OS [4,5]. But the tumor made severe metastatic form to the right axillary lymph node which has a diffuse contribution of osteoid matrix all of the tissue. So, the case is the valuable topic for evaluate the correlation of metastasis to lymph node which is near the primary tumor region and pro gnosis of canine appendicular osteosarcoma. (omitted)