• 치위생과학회지
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• 제24권3호
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• pp.125-133
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• 2024

Background: The management of dental plaque and the appropriate use of oral hygiene tools are crucial for oral health. With increasing interest in oral health care, various oral hygiene products are available on the market. As the most basic oral hygiene tool, the large-head toothbrush has gained significant consumer interest. This study evaluates the suitability of large-head toothbrushes as oral hygiene tools by comparing their efficacy with that of regular-sized toothbrushes. Methods: We evaluated the efficacy of large-head and regular-sized toothbrushes. The amount of dental plaque before and after brushing was measured using quantitative light-induced fluorescence digital (QLF-D) images and the plaque index (PI) in adult participants with more than 28 teeth (n=15/group). After brushing, the collected toothbrushes were rinsed 10 times in clean water, thoroughly dried, and weighed on an electronic scale. Data were analyzed using the Wilcoxon signed-rank test with SPSS Statistics Version 29.0. Results: QLF-D analysis showed a significant decrease in fluorescence intensity scores after use of a regular-sized toothbrush, whereas the scores after use of a large-head toothbrush were not significantly reduced. PI measurements indicated significant reductions in dental plaque for both head types. However, detailed analysis by tooth surface revealed that the regular-sized toothbrush significantly reduced plaque on the proximal, palatal/lingual, and labial/buccal surfaces. In contrast, the large-head toothbrush only showed significant reductions in place on the proximal and palatal/lingual surfaces, not on the labial/buccal surface. Additionally, compared to the regular-sized toothbrush, the large-head toothbrush retained more toothpaste residue despite similar cleaning efforts after brushing. Conclusion: Compared to the regular-sized toothbrush, the large-head toothbrush showed lower overall efficacy in dental plaque removal. The results of this study provide significant information regarding the use of large-head toothbrushes.

• 대한두경부종양학회지
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• 제39권2호
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• pp.59-63
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• 2023

Epstein-Barr virus positive diffuse large B-cell lymphoma is very rare malignant tumor in thyroid gland. Compared to Epstein-Barr virus negative diffuse large B-cell lymphoma, it tends to have more extranodal involvement, does not respond to chemoimmunotherapy well, and has worse prognosis. We have encountered a patient with Epstein-Barr virus positive diffuse large B-cell lymphoma of thyroid gland in 75-year-old female presenting with aggravating dyspnea and neck pain.

• 대한두경부종양학회지
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• 제35권2호
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• pp.45-49
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• 2019

Large cell neuroendocrine carcinoma is a rare epithelial neuroendocrine malignancy and is preferentially located in gastrointestinal tract and pancreas. Cases of large cell neuroendocrine carcinoma have been reported in many other locations, including the thymus, gallbladder, prostate, larynx, salivary glands, nasopharynx, tonsil and mastoid. However, primary sinonasal large cell neuroendocrine carcinoma never have been reported in Korea. We experienced a case of primary large cell neuroendocrine carcinoma arising from left maxillary sinus recently. A 82-year-old male patient presented with nasal obstruction and epistaxis. The biopsy revealed large cell neuroendocrine carcinoma with poor differentiation. After a general evaluation, the patient was staged as cT3N0M0. The patient was treated by combined radiotherapy and chemotherapy. We report this rare case with literature review.

• 임상이비인후과
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• 제29권2호
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• pp.250-253
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• 2018

Schwannomas originating from the external auditory canal are relatively uncommon whereas they are commonly found in head and neck region. The authors recently experienced a 18-year-old male with a large mass in his right side external auditory canal. The mass was reported as a schwannoma and after the local excision, no symptom or sign of recurrence was identified. We report the case with literatures.

• 한국지반환경공학회 논문집
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• 제5권2호
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• pp.33-39
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• 2004

대부분의 말뚝기초는 두부 고정상태이지만, 수평재하시험은 일반적으로 두부 자유상태에서 시행되었다. 이번 논문은 두가지 경우(두부고정, 두부자유)에 대한 말뚝깊이별 수평변위와 이론 방정식과 현장수평재하시험을 비교해가며 대구경현장타설말뚝의 수평거동을 분석한 말뚝현장수평재하시험을 수행하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.36-43
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• 2004

Most of pile foundations are fixed head condition, but lateral loading test for pile is performed under free head condition generally In this study, a lateral loading test for a large diameter drilled shaft was performed under the fixed pile head and the free pile head condition, where lateral displacement along the pile depth was measure. Test results and theoretical values were compared and analyzed.

• 한국안전학회지
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• 제16권2호
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• pp.13-21
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• 2001

The effect of water spray for the fire sprinkler depends on droples distribution over maximum possible floor area. The present study are carried out for the characteristics of water spray and droplets experimentally and numerically km two fire sprinkler heads which are CHM head and CHl heal CHl head is self-production and CHl head is widely used up to date. As the result of using CHM head, water spray and droplets are distributed over large area because CHM head has smooth surface and non-flamed shape. When the pressure of fire sprinkler head is low, SMD(sauter mean diameter) is large and when the pressure of fire sprinkler head is high, SMD is small.

• 대한두경부종양학회지
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• 제19권1호
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• pp.67-70
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• 2003

Out of entire salivary tumor, 1.7% are malignant lymphoma developed in salivary gland and it is usually mucosa associated lymphoid tissue (MALT) lymphoma developed in salivary gland. In the case of Non-Hodgkin lymphoma, the most frequently involved extanodal sites of diffuse large B cell lymphoma are bone, skin, thyroid, gastrointestinal tract, and lung. Development in salivary gland is very rare. A 69 years old male patient who have found Lt. submandibular gland (SMG) mass a month ago is suspected of malignancy from his FNA result, so histologic exam by SMG resection was operated. According to histopathologic exam, large B cell lymphocyte infiltratration were generally shown as diffuse and lymphoepitheliallesion were not found. In immunostaining, CD79a showed positive and CD3, CAM5.2 showed negative which diagnosed as diffuse large B cell lymphoma. As Ann Arbor stage I, CEOP-B chemotherapy was used 3 times as treatment without any recurrence. In the case of malignant lymphoma in salivary gland, it develops as painless mass in ipsilateral side. If found in parotid gland, it is rare to have facial nerve falsy and pathologically diagnosed as lymphocytes of abnormal type of monoclonal immunostaining must be provided as evidence. Combined therapy is known as most effective treatment for intermediate grade.

• 한국생산제조학회지
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• 제22권6호
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• pp.937-944
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• 2013

This paper describes an improved model that can be used for configuring a non-contact pneumatic head to handle a large sheet of glass. The cylindrical head model is of a large size (70 mm). It operates on vortex flow, which can simultaneously generate suction and repulsion over the flat object's surface. The head allows for the minimal non-contact lifting of objects weighing over 3N by using reference conditions (working pressure and head dimensions). Additionally, a functional flow-guide is applied for inducing a developing tangential vortex flow to increase suction and repulsion to the reference head. The cylindrical flow-guide is associated with relatively low tangential velocity. The improved model generates greater lifting force than the reference model, as verified experimentally.

• 대한두경부종양학회지
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• 제24권1호
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• pp.69-72
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• 2008

Lymphomas of the nasal sinuses are relatively uncommon and represent less than 1% of all head and neck malignancies. Most common symptoms are nasal obstruction, epistaxis, rhinorrhea. We report a case of primary extranodal diffuse large B-cell non-Hodgkin's lymphoma in nasal sinuses accompanying with exophthalmos. A 70-year-old male patient was referred to our hospital with exophthalmos and severe septal deviation. We conducted endoscopic biopsy with septoplasty and biopsy result was diffuse large B-cell lymphoma. He received chemotherapy(R-CHOP) and radiotherapy. At follow-up, he remained free of disease.