• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권1호
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• pp.30-35
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• 2011

Introduction: Dental implants are used routinely with high success rates in generally healthy individuals. By contrast, their use in patients with diabetes mellitus is controversial because altered bone healing around implants has been reported. This study examined the bone healing response around titanium implants placed immediately in rats with controlled and uncontrolled diabetes. Materials and Methods: Twenty rats were divided into the control, insulin-treated and diabetic groups. The rats received streptozotocin (60 mg/kg) to induce diabetes; animals in the insulin-treated group also received three units of subcutaneous slow-release insulin. A titanium implant ($1.2{\times}3\;mm$) was placed in the extraction socket of the maxillary first molar and bone block was harvested at 1, 2 and 4 weeks. Results: Bone formation around the implants was consistently (from 1 to 4 week post-implantation) slower for the diabetic group than the control and insulin-treated group. Bone morphogenesis in the diabetic rats was characterized by fragmented bone tissues and extensive soft tissue intervention. Conclusion: The immediate placement of titanium implants in the maxilla of diabetic rats led to an unwanted bone healing response. These results suggest that immediate implant insertion in patients with poorly controlled diabetes might be contraindicated.

• 치위생과학회지
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• 제19권3호
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• pp.198-204
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• 2019

Background: Oxidative stress is a known to be associated with in the pathogenesis of many inflammatory diseases, including periodontitis. Ursolic acid is a pentacyclic triterpenoid with has antimicrobial, antioxidative, and anticancer properties. However, the role of ursolic acid in the regulating of osteogenesis remains undetermined. This study was aimed to elucidate the crucial osteogenic effects of ursolic acid and its ability to inhibit oxidative stress by targeting the immediate early response 3 (IER3)/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Methods: Cell proliferation was determined using water-soluble tetrazolium salt assay, cell differentiation was evaluated by alkaline phosphatase (ALP) activity, and formation of calcium nodules was detected using alizarin red S stain. Generation of reactive oxygen species (ROS) was determined using by DCFH-DA fluorescence dye in hydrogen peroxide ($H_2O_2$)-treated MG-63 cells. Expression levels of IER3, Nrf2, and heme oxygenase-1 (HO-1) were analyzed using western blot analysis. Results: Our results showed that ursolic acid up-regulated the proliferation of osteoblasts without any cytotoxic effects, and promoted ALP activity and mineralization. $H_2O_2$-induced ROS generation was found to be significantly inhibited on treatment with ursolic acid. Furthermore, in $H_2O_2$-treated cells, the expression of the early response genes: IER3, Nrf2, and Nrf2-related phase II enzyme (HO-1) was enhanced in the presence of ursolic acid. Conclusion: The key findings of the present study elucidate the protective effects of ursolic acid against oxidative stress conditions in osteoblasts via the IER3/Nrf2 pathway. Thus, ursolic acid may be developed as a preventative and therapeutic agent for mineral homeostasis and inflammatory diseases caused due to oxidative injury.

• 대한물리의학회지
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• 제18권3호
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• pp.47-53
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• 2023

PURPOSE: A visual feedback method was proposed to induce brain stimulation in a stroke patient, and among them, there was a treatment using a mirror. On the other hand, mirror therapy focuses only on the functional changes in body movements, and analysis of neurophysiological mechanisms of brain activity is lacking. In addition, studies on evaluating the activity and response generated in specific brain regions during visual feedback training using mirrors are insufficient. METHODS: Fifteen healthy adults (male: 10, female: 5, Years: 23.33 ± 1.23), who were right-handed were recruited. By attaching the C3, Cz, and C4 channels in the sensorimotor cortex using an electroencephalogram, training was performed under the conditions without mirror-based visual feedback (No-condition) and with visual feedback (Tasks-condition). At this time, the immediate activity of the mu-rhythm in response to training was separated and evaluated. RESULTS: The tasks-condition of C3, Cz, and C4 channels activated the relative mu-rhythm rather than the no-condition, and all showed significant differences (p < .05). In addition, in all channels at the start time, the tasks-condition was more active than the no-condition (p < .05). The activity of the cortical response was higher in the tasks-condition than in the no-condition (p < .05). CONCLUSION: The mu-rhythm activity can be evaluated objectively when visual feedback using a mirror is applied to healthy subjects, and a basic analysis protocol is proposed.

• 한국멀티미디어학회논문지
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• 제22권8호
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• pp.940-949
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• 2019

Classroom response systems (CRS) have been proven to have positive educational effects on student engagement and participation by allowing immediate feedback to both students and instructors. We explore the use of a chatbot and slide widget-based CRS to overcome some of the challenges of existing mobile-based CRSs while retaining their advantages. Our system uses widely available instant messaging services and operates web-based slide widgets that can be seamlessly integrated into instructors' slides to visualize student feedback in various formats. The student survey results indicate that our system is as effective as conventional CRSs in promoting student engagement and participation.

• 영재교육연구
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• 제20권3호
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• pp.721-741
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• 2010

이 연구는 중학교 일반학급과 영재학급의 과학수업을 관찰하여 교사의 발문과 피드백, 학생의 응답에 대한 유형과 빈도 분석을 통해 교사와 학생사이의 언어적 상호작용을 비교 분석한 것이다. 연구 결과, 일반학급의 과학수업에서 교사들은 교과서의 내용을 정리해서 묻거나 그대로 안내하는 발문을 많이 사용하였고, 재진술 형태의 즉각 피드백을 주로 사용하였다. 학생들은 네, 아니오, 와 같은 단순 확인 단답형 응답을 많이 사용하였으며, 언어적 상호작용 모형은 인지 기억적 사고 발문-단답형 응답-즉각 피드백 순서가 가장 많았다. 영재학급의 과학수업에서 교사들은 이유가 뭐에요? 왜 그런 거예요? 와 같은 개방적 발문의 확산적 사고 발문과 평가적 사고 발문을 사용하였고, 설명형 형태의 즉각 피드백을 주로 사용하였다. 일반학급과 비교하여 지연 피드백은 높게 나타났으나 즉각 피드백은 낮게 나타났다. 학생들은 짧은 단어나 간단한 문장 형태의 단답형으로 응답하였으며, 수업참여가 보다 적극적이었다. 언어적 상호작용 모형은 인지 기억적 사고 발문-문장 형태 단답형 응답-지연 피드백 순서가 많았다.

• 한국재난정보학회 논문집
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• 제5권2호
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• pp.50-73
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• 2009

This paper is about the establishment of "Initial Response System." Initial response system is most important and should be treated urgently among all preparations for chemical terrorism. The objects of Initial response system are to protect civilians and the first responder who are exposed directly to chemical terrorism. Therefore, this paper suggests two main issues about Initial response system. One is to prepare immediate and exact information service system which assures the safety and survival of exposed people. The other is to build Scene Response System integrated with Command-Control Procedure for early finished situation. Compared to United States, overcoming the Chemical Terrorism requires to improve the contents of two categories: Counter Citizen Response part and Initial Scene Response part. For Counter citizen response part' s sake, the web-sites of Response leader agencies for searching information about chemical terrorism should be modified specifically. These web-sites have to be re-organized in detail. The existing Information service system which has been vaguely informed as "CBRNE Accident" needs to be divided as "CBRNE Accident" and "WMD terrorism." Further, each of them should be specialized in "Chemical', "Biological", and "Radiological" categories. There is a need to rearrange current Emergency Instruction for civilians against chemical terrorism in feasible way. At the same time, it should be applied consistently to all organizations through agreement between experts and related-organizations. For Initial Scene Response part's sake, "Initial scene response procedure (SOP)" and "Operational conception" should be produced through Simulated Exercises and workshops of all organizations related with initial response. These organizations have to cooperate with Ministry of Environment which is the main leader Agency as the center. Next, there is a need to develop a technology and Scene Response Equipments, and to standardize the response equipments which consider the capability of First Responders for chemical terrorism. Especially, improving capability of equipments is required to overcome the vulnerability of Scene Response Equipments.

• Biomolecules & Therapeutics
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• 제16권4호
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• pp.299-305
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• 2008

Active cardiovascular anaphylactic response was induced in ovalbumin-sensitized, pithed Sprague-Dawley and Wistar rats. On intravenous administration of the antigen, ovalbumin, marked tachycardia and pressor responses were immediately elicited. Thereafter, a delayed long-lasting severe hypotensive response was observed. These anaphylactic cardiovascular responses were maximal 2-3 weeks after the sensitization, and the response was slightly diminished 6 weeks after sensitization. The immediate pressor response was blocked by a non-selective serotonin antagonist methysergide at a dose-dependent manner, but not by histamine receptor antagonists mepyramine (pyrilamine) or cimetidine. The delayed hypotension was reduced either by histamine $H_1$ receptor antagonist mepyramine or $H_2$ receptor antagonist cimetidine, both in a dose-dependent manner. The tachycardic response was not influenced by serotonin or histamine receptor antagonists examined in this study. Differently from the cardiovascular responses, there was no observable bronchial contraction in Sprague-Dawley rat trachea in contrast to Wistar rat where the trachea contracted to in vitro antigen challenge. The cardiovascular anaphylactic model seems to be useful for studying cardiovascular events that occur exclusively in peripheral heart-blood vessel systems. The involvement of two major anaphylactic mediators, serotonin and histamine, is partially demonstrated.

• 한국가스학회지
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• 제9권2호
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• pp.43-49
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• 2005

현재 여러 가지 목적으로 사용되고 있는 독성가스는 누출사고 발생시 확산되는 특성이 있어 피해 범위가 매우 넓고, 인체에 치명적이라는 특징을 가지고 있다. 따라서, 위험성이 높은 독성가스 이용시설은 누출사고에 대비한 사고 대응 시스템을 구축하여 비상상황 발생시 즉각 대응이 가능하도록 하여야 한다. 이에 본 연구에서는 FTA기법을 이용한 사고 시나리오 선정 및 빈도 분석과 DNV사의 PHAST(Ver 6.2)를 이용하여 독성가스 누출에 의한 확산 사고영향 분석을 실시하였다. 그리고, 정량적 위험성 평가 결과들을 이용하여 독성가스시설의 비상대응시스템을 구축하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.319-322
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• 2005

When a concrete structure is subjected to load, its response is both immediate and time dependent. Under sustained load, the deformation of a structure gradually increases with time and eventually may be many time greater than its instantanneous value. The gradual development of strain with time is caused by creep and shrinkage. On this study, to estimate of stress variations on time effects in partially prestressed concrete composite girder bridges, computer program applied Age-adjusted Effective Modulus Method(AEMM) in used.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.87-90
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• 2005

An experimental investigation of the basic characteristics of a micro-cantilever sensor was performed by inspecting the amplitude and frequency characteristics using a commercial tuning fork. Application of acetone and ethanol with a volume of $1 {\mu}l$ on the tine of a vibrating tuning fork cause immediate response in its amplitude and frequency. It has shown that the tuning fork has ability to recognize a chemical agent with high sensitivity.