• Journal of the Korean Regional Science Association
• /
• v.33 no.3
• /
• pp.49-59
• /
• 2017

The piezoelectric energy harvester is recently being developed and catching on as a way to achieve low carbon green growth. The practical application of the piezoelectric energy harvester is expected to contribute not only to the reduction of greenhouse gas emissions but also to the improvement of residents' welfare. This paper conducted a cost-benefit analysis for the installation of piezoelectric energy harvester on the highway focusing on its impacts on the public. The results showed that the installation of piezoelectric energy harvester on the gyeongbu highway is economically feasible in that it could increase the social welfare for the residents. Finally, this paper suggests policy direction for the practical use of the piezoelectric energy harvester, based on the results obtained.

• Restorative Dentistry and Endodontics
• /
• v.29 no.1
• /
• pp.1-12
• /
• 2004

이 연구는 발거 소구치에서 5급 와동을 형성하여 접착 시스템 및 와동 위치에 따른 상아질에 대한 접착시스템의 미세 인장결합강도의 차이를 비교, 연구하였다. 접착방법은 resin-modified glass ionomer(Gl), compomer(부식여부에 따라 DE 및 DN군으로 분류), 그리고 상아질 접착제인 Single Bond(SB) 및 Cleayfil SE Bond(SE)와 복합레진(Clearfil AP-X)을 사용한 5개의 실험군으로 분류하였다. 소구치 협측 치경부에 wedge형태의 와동을 형성하고 5종의 접착 시스템을 제조자의 지시에 따라 적용, 충전하여 시편을 제작하여 미세인장결합강도를 측정하고, One-way ANOVA / Duncan's test로 통계분석하였다. SEM 검사는 미세인장결합강도의 시편제작과 동일한 방법으로 시편을 제작한 후 관찰하였다. 실험 결과, 상아질 접착제 및 복합레진(SB, SE)의 미세인장결합강도가 GI보다 높게 나타났고(p<0.05), 치은측이 교합측보다 더 낮게 나타났으며, CI, DE, SE에서 유의성 있게 낮게 나타났다(p<0.05). Compomer에서 conditioning 여부(DN, DE)에 따른 변화는 치은측에서만 유의차 있는 것으로 나타났다. SEM 관찰에서, 교합측의 상아세관은 결합 계면과 평행하게 주행하였고, 치은측에서는 결합계면에 수직으로 주행하는 것으로 관찰되었다.

• Korean Journal of Bronchoesophagology
• /
• v.17 no.2
• /
• pp.120-123
• /
• 2011

A bronchogenic cyst is an uncommon benign congenital anomaly of the primitive ventral forgut which was generally encountered within the mediastinum and detected in pediatric patients. It is rarely detected in adult population as a lateral neck mass. We have recently experienced one case of bronchogenic cyst as a left lateral neck mass in a 49-year-old male. He complaints of a $2{\times}1$ cm sized, soft, non tender, and movable mass on the low lateral neck. The surgical excision of mass was performed and the final histopathologic diagnosis was a bronchogenic cyst. Here, we report this case with the review of literatures.

• Korean Journal of Head & Neck Oncology
• /
• v.15 no.1
• /
• pp.89-91
• /
• 1999

We experienced a case of the papillary thyroid carcinoma seen as a huge solid lateral neck mass. The mass grew very slowly over the period of 30years up to 10cm in diameter while relatively well sparing the surrounding tissues. Physical examinations, CT scan, and fine needle aspiration cytology did not reveal any strong suggestions for evidence of malignancy. But it was pathologically diagnosed as metastatic thyroid carcinoma by excisional biopsy. We emphasize that for a large solitary neck mass which persists for several decades, head and neck surgeons should always keep in mind the possibility of metastasis from the malignancy of thyroid gland.

• Korean Journal of Head & Neck Oncology
• /
• v.4 no.1
• /
• pp.53-58
• /
• 1988

We have experienced 3 cases of papillary carcinoma of the thyroid gland seen as lateral neck cyst, Usually cystic lesions of the neck have been considered as benign lesions from clinical viewpoint. The usual differential diagnosis includes branchial cleft cyst, cystic hygroma, dermoid cyst, cold abscess(tuberculous lymphadenitis) and cavitating squamous cell carcinoma. A lateral neck cyst as the sole presenting complaint of the papillary thyroid carcinoma is very rare. Preoperative diagnosis of lateral neck cyst is often diagnostic dilemma. Fine-needle aspiration cytology can be helpful in detecting the cancer cells and in demonstrating the nature of the fluid component of the lateral neck cyst. Presence of brown murky fluid from the aspirated fluid is highly suggestive of thyroid carcinoma. The thyroid scans and B-mode ultrasonography mayor may not be helpful to detect the primary focus of the thyroid gland. We suggest that a patient with a lateral neck cyst in adult age group should be considered to be a possibility of underlying thyroid carcinoma presanting as lateral neck cyst.

• Korean Journal of Food Science and Technology
• /
• v.32 no.6
• /
• pp.1389-1395
• /
• 2000

Cervical cancer has been one of the leading causes of female death from cancer worldwide with about 500,000 deaths per year. A strong association between certain human papillomaviruses (HPV types 16 and 18) and cervical cancer has been well known. An extract of natural products, Rhus, has been used to investigate whether this agent has the ability of inhibiting the oncogenes E6 and E7 of HPV type 16. This Rhus inhibited the proliferation of human cervical cancer cell lines (C-33A, SiHa, Caski) and HaCaT keratinocytes in a dose response manner. In vitro binding assay and ELISA showed that Rhus inhibited the in vitro binding of E6 and E6AP which are essential for the binding and degradation of the tumor suppressor p53. In addition, Rhus inhibited the in vitro binding of E7 and Rb which essential tumor suppressor for the control of cell cycle. The level of mRNA for E6 was also decreased by Rhus while that of E7 mRNA was not changed. Our data suggested that Rhus inhibited the oncogenecity of E6 and E7 of HPV 16 type, thus can be used as a putative anti-HPV agent for the treatment of cervical carcinomas by HPV.

• The Journal of Korean Academy of Prosthodontics
• /
• v.48 no.3
• /
• pp.224-231
• /
• 2010

Purpose: This study was to investigate how the crestal module design could affect the level of marginal bone stress around dental implant. Materials and methods: A submerged implant of 4.1 mm in diameter and 10 mm in length was selected as baseline model (Dentis Co., Daegu,Korea).A total of 5 experimental implants of different crestal modules were designed (Type I model : with microthread at the cervical 3 mm, Type II model : the same thread pattern as Type I but with a trans-gingival module, Type III model: the same thread pattern as the control model but with a trans-gingival module, Type IV model: one piece system with concave transgingival part, Type V model: equipped with beveled platform). Stress analysis was conducted with the use of axisy mmetric finite element modeling scheme. A force of 100 N was applied at 30 degrees from the implant axis. Results: Stress analysis has shown no stress concentration around the marginal bone for the control model. As compared to the control model, the stress levels of 0.2 mm areas away from the recorded implant were slightly lower in Type I and Type IV models, but higher in Type II, Type III and Type V models. As compared to 15.09 MPa around for the control model, the stress levels were 14.78 MPa, 18.39 MPa, 21.11 MPa, 14.63 MPa, 17.88 MPa in the cases of Type I, II, III, IV and V models. Conclusion: From these results, the conclusion was drawn that the microthread and the concavity with either crestal or trans-gingival modules maybe used in standard size dental implants to reduce marginal bone stress.

• The korean journal of orthodontics
• /
• v.25 no.4
• /
• pp.433-445
• /
• 1995

Tooth movement, the phenomena and mechanisms of which are still controversial, can be considered as part of the result of the inflammatory processes. The purpose of this study was to examine the activity of macrophage and T-cell, playing important roles in the immune reaction, in the periodontal ligament of dog, in which experimental tooth movement was performed. Six one and half year-old dogs, a control and 5 experimentals, were studied. Light force (50-75g) was applied by placing open-coil spring between left mandibular premolars ; heavy force (250-300g), between right mandibular premolars. Experimental dogs were sacrificed at 12 hours, 1, 3, 7 and 14 days since force application, respectively. And the histologic and the immunohistochemical evaluation on the obtained tissue were performed, using $\alpha$-1-antichymotrypsin and CD3 antibodies. The results were as follows : 1. There were more inflammatory cell infiltrations in heavy force group than in light force group until 3 days. But from 7 dsays on, no difference was not observed between groups ; Such an infiltration was more evident at pressure side than at tension side. 2. Osteoclastic activity at pressure side began to be seen in 12 hours, increasing until 7 days. After then it decreased ; Such an activity was more evident in heavy force group than in light force group. 3. Tearing of periodontal ligament and vascular dilatation at tension side began to be seen in 12 hours, increasing until 3 days. After then it decreased ; Such an observation was more evident in heavy force group than in light force group, but there was no difference between groups in 14 days. 4. $\alpha$-1-antichymotrypsin expression in control group was positive, mainly in sulcular epithelium, but negative in periodontal membrane, pulp, bone cells. 5. $\alpha$-1-antichymotrypsin expression in experimental group was more positive in pressure side than in tension side ; The expression was a little more positive in cervical area of tooth until 3 days, but after 7days, it was more positive in apical area. 6. $\alpha$-1-antichymotrypsin expression in light force group began to be observed in 12 hours and reached to the greatest level in 7 days, after which it decreased ; In heavy force group, it was the greatest in 3 days, after which it decreased. 3 Expression in the periodontium was almost negative.

• The korean journal of orthodontics
• /
• v.25 no.1 s.48
• /
• pp.31-42
• /
• 1995

This study was designed to evaluate the expression of growth factor in periodontal tissue during the experimental movement of rat incisors by LSAB(Labelled streptavidine Biotin) immunohistochemical staining for EGF(Epidermal growth factor). 23 Sprague-Dawley rats were divided into a control group(3rats) and experimental groups(20rats), where a force(75g) from helical springs across the maxillary incisors was applied. Experimental groups were sacrificed at 12 hours, 1, 4, 7 and 14 days, after force application, respectively. And Tissue slides of control and experimental groups were studied immunohistochemically and histologically. The results were as follows : 1. In 14days after force application, periodontal fibers were strectched on the tension side, and compressed In pressure side of all experimental groups, and the arrangement of periodontal fibers was not recovered yet. 2. The degree of EGF expression in control group was strongly positive in the oral epithelium, predentin, capillaries in pulp and periodontal spaces. But osteoblasts and osteoclasts were stained mildly positive. 3. EGF expression was mild and diffuse in 12 hours, 1, 4 and 7 days of experimental groups and was not significantly different between the tension and pressure sides. 4. The degree of EGF expression in the 14-day experimental group was higher than any other group. And the tension side showed a more positive EGF expression than the pressure side. The apical area revealed a more positive EGF expression than the cervical area.

• Korean Journal of Head & Neck Oncology
• /
• v.26 no.2
• /
• pp.232-235
• /
• 2010

Extraparotid Warthin's tumor(EPWT) is a rare disease entity; its incidence is about 8% of Warthin's tumor(WT). The periparotid and upper cervical lymph nodes are the most predilection sites. The lymphoid tissue of WT can act like a regional lymph node, and the necrosis and inflammation within the tumor are well known. In our cases, both 81-year-old man and 58-year-old man were visited our clinic, presented with upper lateral neck mass that had been present for the last few months. We operated the excisional biopsy in level ll of neck. The pathologic examination was proven to be EPWT. We report the unique two cases of extraparotid Warthin's tumor with literature review.