• Journal of Periodontal and Implant Science
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• 제30권1호
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• pp.145-157
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• 2000

Cytotoxic substances in dental calculus and root cementum of periodontally diseased teeth inhibit new attachment and regeneration. The purpose of scaling and root planing is to remove pathologic structures harboring these cytotoxic substances in order to create a biologically acceptable root surface. However, these procedures inevitably leave a non-biocompatible smear layer. Conventionally, the smear layer has been removed with low pH etching agents such as citric acid, phosphoric acid and tetracycline hydrochloride(TC). Lately, a supersaturated neutral pH etching solution of ethylene diamine tetraacetic acid(EDTA) has been found to be as effective as low pH etchants with respect to smear removal and to be superior in exposing root surfaceassociated collagen. The aim of the present study was to determine the effect of root surface treatment using EDTA on the initial attachment of human gingival fibroblasts. 27 human teeth, extracted due to severe periodontitis, were cut into dentin slices after root planing. The specimens were divided into TC group(treated with $50㎎/m{\ell}$ tetracycline-HCl, pH 1.52), EDTA group(treated with 17% EDTA, pH 7.4), and non-treated control group. After sterilization, 5th subcultured human gingival fibroblasts were seeded in each culture well containing a prepared root slice and incubated for 15 min., 60 min., and 4 hours in 5% $CO_2$ incubator at $37^{\circ}C$. At each incubation time, the number of attached fibroblasts were counted on the microphotographs taken at a magnification of x100. The difference of the number of attached cells between groups was statistically analyzed by the ANOVA followed by Duncan test in SPSS/PC＋programs. The results were as follows : 1. After incubation for 15 min, the attached cells were significantly more in EDTA group and TC group than non-treated control group(p<0.05), but there was no significance in the difference between EDTA group and TC group(p>0.1). 2. After incubation for 60 min and 4 hours, there was no significant difference in the number of attached cells between all groups(p>0.1). 3. In both EDTA group and TC group, there was no significant difference in the number of attached cells between different incubation(p>0.1). But in control group, the number of attached cells was significantly increased after incubation for 60 min, compared with incubation for 15 min(p<0.05). The above results suggest that root surface treatment using EDTA could enhance the initial attachment of gingival fibroblasts to root surface as effective as tetracycline-HCl.

• 한국광물학회지
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• 제28권4호
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• pp.309-323
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• 2015

본 연구에서는 폐금속 광산에 특화된 인체위해성평가 방법을 제시하고, 국내 폐금속 광산지역으로부터 도출된 다양한 노출인자 값을 적용하여 폐금속 광산지역의 주민(성인 남자, 성인 여자, 어린이)에 대하여 인체위해성평가를 수행하였다. 또한 인체위해성평가의 결과로부터 중금속 오염에 의한 주민의 건강이 우려되는 경우, 위해성에 기반한 각 매체(토양, 지하수, 지표수)별 복원기준을 제시하고자 하였다. 본 연구 결과, 발암위해도와 비발암위해도를 지시하는 총 초과발암위해도(TCR)와 위험지수(HI)는 지하수섭취와 농작물섭취에 의한 경로로 노출되는 비소에 의해 각각 허용 가능한 수준인 1.00E-6과 1을 크게 초과하는 것으로 나타나서 연구대상 지역의 인체위해성이 큰 것으로 평가되었다. 위해도 저감을 위한 복원농도 산정 결과, 발암위해도 기준 계산 시 As 6.83~6.85 mg/kg, Pb 18.41~18.46 mg/kg, 비발암위해도 기준 계산 시 Cu 17.38 mg/kg, As 9.13 mg/kg의 수준으로 토양정화가 필요한 것으로 나타났다.

• 한국콘텐츠학회논문지
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• 제22권1호
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• pp.391-404
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• 2022

행위자-관계망 이론(ANT)은 인간과 비인간 행위자간의 관계적 효과를 주목하며 비인간을 인간과 같은 행위자로 간주함으로서 이들 행위자간의 수많은 네트워크를 변역한다. 본 논문은 ANT를 통해 NCS기반 교육과정이 도입되는 전후 맥락과 관계되는 다양한 비인간행위자에 대해서 살폈다. 이러한 접근은 새로운 제도가 도입됨에 따라 기존의 관계망에 미치는 영향 및 갈등상황을 보다 면밀하게 살펴 볼 수 있기 때문이다. 이를 위해 연구자는 S대학에서 NCS기반 교육과정 도입여부가 논의된 2014년 10월부터 실질적인 운영이 진행되어 졸업생이 배출된 2017년 2월까지의 자료를 검토하였으며, S대학의 NCS기반 교육과정 도입과정을 이해하기 위해 ANT이론에서 Callon이 주장한 번역의 4단계를 토대로 분석하였다. 그 결과, NCS기반 교육과정이 도입된 S대학 교육과정 개편 사례에서 몇 가지 의미를 확인하였다. 첫째, 기존의 교육과정에 대한 연구가 간과했던 교육과정을 둘러싼 상황을 심층적으로 분석했다는 점이다. 둘째, 대학내에서 교육과정이 갖는 '피상적 의미'를 넘어서 '숨겨진 의미'를 해석하는데 기여했다. 셋째, 대학에 새로운 제도가 도입되는 과정에서 나타나는 기존 제도와의 충돌과 갈등 상황을 간접적으로 확인해 볼 수 있었다.

• 대한지구과학교육학회지
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• 제14권1호
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• pp.21-32
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• 2021

본 연구는 우리 사회를 구성하는 일반 시민으로 성장할 대학생들을 대상으로 미래의 지구 환경에 대한 인식을 조사하였다. 비과학 전공의 대학생들은 자연물과 인공물의 복합적 공간으로 인식하고 있는 비율이 매우 낮았다. 또한 현재에서 미래로 지구 환경의 변화에 대해 부정적으로 인식하는 비율이 높았다. 대학생들이 상상하는 미래의 지구 환경의 이미지에서 자연과 함께 생존하는 인간이 그려질 수 있도록 환경 인식이 달라져야 한다. 인간이 자연과 공존할 수 있는 방향으로 더불어 공존하는 방법을 찾아 실천하는 환경 교육이 이루어져야 할 것이다. 또한 비과학 전공의 대학생들은 미래의 지구 환경을 인간이 수정하는 공간으로 내면화 하는 비율이 높았다. 이러한 결과는 인간 행동에 의해 지구 환경이 수정될 수 있다는 관점을 나타내는 것으로 해석되며 대학에서 제공해야 하는 환경 교육의 방향을 제시한다. 환경에 대한 교육이나 환경으로부터의 교육이 아닌 환경을 위한 교육으로 대학의 환경 교육 방향이 전환되어야 한다. 대학 교육과정에서 전공 여부에 차별 없이 모든 대학생들에게 지구 환경 교육의 기회를 제공하여야 한다. 우리의 아들딸들이 지구에서 지속적으로 살아가기 위해서는 지속 가능한 지구 환경 교육이 절실하게 필요하다.

• BMB Reports
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• 제51권11호
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• pp.584-589
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• 2018

Secondary prevention via earlier detection would afford the greatest chance for a cure in premalignant lesions. We investigated the exomic profiles of non-malignant and malignant changes in head and neck squamous cell carcinoma (HNSCC) and the genomic blueprint of human papillomavirus (HPV)-driven carcinogenesis in oropharyngeal squamous cell carcinoma (OPSCC). Whole-exome (WES) and whole-genome (WGS) sequencing were performed on peripheral blood and adjacent non-tumor and tumor specimens obtained from eight Korean HNSCC patients from 2013 to 2015. Next-generation sequencing yielded an average coverage of $94.3{\times}$ for WES and $35.3{\times}$ for WGS. In comparative genomic analysis of non-tumor and tumor tissue pairs, we were unable to identify common cancer-associated early mutations and copy number alterations (CNA) except in one pair. Interestingly, in this case, we observed that non-tumor tonsillar crypts adjacent to HPV-positive OPSCC appeared normal under a microscope; however, this tissue also showed weak p16 expression. WGS revealed the infection and integration of high-risk type HPV16 in this tissue as well as in the matched tumor. Furthermore, WES identified shared and tumor-specific genomic alterations for this pair. Clonal analysis enabled us to infer the process by which this transitional crypt epithelium (TrCE) evolved into a tumor; this evolution was accompanied by the subsequent accumulation of genomic alterations, including an ERBB3 mutation and large-scale CNAs, such as 3q27-qter amplification and 9p deletion. We suggest that HPV16-driven OPSCC carcinogenesis is a stepwise evolutionary process that is consistent with a multistep carcinogenesis model. Our results highlight the carcinogenic changes driven by HPV16 infection and provide a basis for the secondary prevention of OPSCC.

• 한국산학기술학회논문지
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• 제10권4호
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• pp.771-784
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• 2009

조직의 환경이 불확실성이 높고 동태적인 상황에서는 유형 자산 보다는 지식 기반의 무형 자신을 확보하여 차별적인 경쟁 우위를 먼저 확보하고 이를 유지할 수 있도록 하여야 할 것이다. 특히 서비스 산업에서의 인적 자원 관리는 매우 중요하다 하겠다. 본 연구에서는 선행 연구를 바탕으로 IT 기반의 정보 시스템으로서의 e-HRM 시스템에 대해서 도입 요인과 조직의 성과를 연구하였다. 연구 결과, 첫째, 정보 기술 요인 중 IS 성숙도는 조직 성과에 영향을 미치는 것으로 나타났으며, IS/IT 기반 구조는 재무적 성과에만 유의한 영향을 미치는 것으로 나타났다. 둘째, 환경 요인 중 경쟁 정도, 정보화 정도, 환경 불확실성 요인들은 재무적 성과에 영향을 미치는 것으로 나타났으나, 비 재무적 성과에는 영향을 미치지 않는 것으로 나타났다. 셋째, 조직의 규모는 정보 기술 요인 및 환경 요인과 조직성과 간에 부분적으로 조절적 역할을 하고 있음을 알 수 있었다. 따라서 서비스 산업에서는 조직의 규모가 큰 경우에는 e-HRM 시스템을 도입하는 것이 조직의 재무적 성과의 향상에 효과적이라는 결론을 조심스럽게 내릴 수 있었다.

• Journal of Periodontal and Implant Science
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• 제24권3호
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• pp.661-670
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• 1994

It is well known that the application of dressings after periodontal surgery have benefits to provide the comforts to patient and to promote the healing process with action of bleeding control and temporary stabilization for the operated mobile teeth. But until recently the relationship between periodontal dressings and cells which are composed of periodontium has not been clear. The purpose of this study was to evaluate the cytotoxic effect of soluble extracts from the four different kinds of periodontal dressings, two of them were eugenol type (K.H.pack, Wondrpak) and the others were non-eugenol type (Coe-pak, Periocare), on the human gingival fibroblasts in vitro. Human gingival fibroblasts were primarily cultured from gingiva around third molar during the extraction for preventive purposes. Extracts solution were prepared with culture medium by means of imersing the consistent size of periodontal dressing made from plastic mold. Cell were inoculated into the 24 well plate with $3\;{\times}\;10^4\;cells/well$ of medium at $37\;^{\circ}C$, 100% of humidity, 5% of $CO_2$, incubator for 24 hours. After discard of the supernatant of medium, those cells were cultured with original, 1/2, 1/5, 1/10 diluted soluble extract for 24, 48 and 72 hours, and counted the number of cells using the hemocytometer at each designed time and concentration. Also, the cytotoxic effect of soluble extract was measured by Wataha's MTT assay method. In briefly, cells were inoculated and cultured into 96 well culture plate with $2\;{\times}\;10^4\;cells/well$ for 24 hours. Soluble extracts were applied to cultured cells and incubated for 48 hours at same condition. $50\;{\mu}l$ of MTT solution and DMSO were added into each well for the detection of absorbance with ELISA reader. The measured data were calculated by value of colorimetric assay for survival rate. The results were as follows ; In the case of eugenol type of dressing, original, 1/2 and 1/5 diluted extracts of K.H.pack showed very low survival rate. And original extract of Wondrpak showed strong cytotoxic effect and 1/2 diluted extract showed moderate cytotoxic effect. In the case of Non-eugenol type of dressings, only original extract of Coe-pak revealed strong cytotoxic effect and Periocare had little cytotoxic effect. It is concluded that eugenol type of dressings showed more cytotoxic effect than non-eugenol types. This study suggest that use of non-eugenol dressings after periodontal surgery is recommended.

• 대한한방내과학회지
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• 제28권3호
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• pp.473-491
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• 2007

Objectives : This study was designed to investigate the antiproliferative activity of the water extract of Samgibopae-tang (SGBPT) in NCI-H460 and A549 non-small-cell lung cancer cell lines Methods : In this study, we measured the subsistence, form of NCI-H460 and A549 non-small-cell lung cancer cell by hemocytometer and DAPI staining. In each cell, we analyzed DNA fragmentation. reverse transcription-polymerase chain reaction and measured activity of caspase-3, caspase-8 and caspase-9. Results and Conclusions : We found that exposure of A549 cells to SGBPT resulted in growth inhibition in a dose-dependent manner. butSGBPT did not affect the growth of NCI-H460 cells. The antiproliferative effect by SGBPT treatment in A549 cells was associated with morphological changes. SGBPT treatment partially induced the expression of DR5 cells and the expression of Faswas markedly increased in both transcriptional and translational levels in A549 cells. SGBPT treatment partially induced the expression of Bcl-2, Bcl-XL and the expression of Bid was markedly decreased in translational levels in A549 cells. However, SGBPT treatment did not affect the expression of IAP family in A549 orNCI-H460 cells. SGBPT treatment partially induced the expression of caspase-3, caspase-8, caspase-9 activity which markedly increased in a dose-dependent manners in A549 cells. The fragmental development of PARP and ${\beta}$-catenin protein was observed in A549 cells by SGBPT treatment. SGBPT treatment induced the expression of PLC-${\gamma}1$ protein which decreased in A549 cells. SGBPT treatment partially induced the expression of DFF45/ICAD which markedly increased in a dose-dependent manner in A549 cells. Taken together. these findings suggested that SGBPT-induced inhibition of human lung carcinoma did not affect NCI-H460 cell growth. However, SGBPT-induced inhibition of human lung carcinoma A549 cell growth was associated with the induction of death receptor and mitochondrial pathway. The results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of SGBPT.

• 대한의용생체공학회:의공학회지
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• 제25권6호
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• pp.519-523
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• 2004

골다공증이 있는 대퇴골두 해면골과 골다공증이 없는 대퇴골두 해면골의 특성을 평가하고자 미세단층촬영기 및 유한요소모델을 이용하여 해면골을 미세구조 특성과 기계적 특성을 비교 및 분석하였다. 골다공증이 있는 대퇴골두는 골밀도를 측정하여 T-score 값이 -2.5 이상인 시편 15개를 사용했으며, 골다공증이 없는 대퇴골두는 사망전 골다공증으로 인한 병력이 없었던 사체 4구에서 대퇴골두 5개를 획득하여 사용하였다. 대퇴골두 해면골의 미세구조 특성을 분석하기 위해서 미세단층촬영기를 이용하여 골다공증이 있는 대퇴골두와 골다공증이 없는 대퇴골두를 촬영하여 형태학적 지수(histomorphometry index)를 구했고, 미세단층촬영기에 의해서 획득된 미세영상(pixel size=21.31㎛)을 바탕으로 유한요소모델을 재건하여 기계적 특성을 구하였다. 형태학적지수는 골다공증이 없는 대퇴골두가 골다공증이 있는 대퇴골두에 비해서 골소주 두께, 골 체적, 골 체적비, 이방성 정도 그리고 골소주 개수가 증가했으며, 골소주 간격과 구조모델지수는 감소했다. 기계적특성 지수는 골다공증이 없는 대퇴골두 해면골 시편에서 반력, 표면응력 그리고 영률이 높게 분석되었다. 골다공증이 있는 대퇴골두 해면골 시편에서 미세구조 특성이 퇴화되며, 기계적 특성이 감소된다는 사실을 알수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권3호
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• pp.402-413
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• 2001

Food safety is a term broadly applied to food quality that may adversely affect human health. These include zoonotic diseases and acute and chronic effects of ingesting natural and human-made xenobiotics. There are two major areas of concern over the presence of residues of antibiotics in animal-derived foodstuffs with regard to human health. The first is allergic reactions. Some antibiotics, such as penicillins can evoke allergic reactions even though small amounts of them are ingested or exposed by parenteral routes. The second is development of antibiotic resistance in gut bacteria of human. Recently multi-resistant pneumococcal, glycopeptide-resistant enterococci and gram negative bacteria with extended-spectrum $\beta$-lactamases have spread all over the world, and are now a serious therapeutic problem in human. Although it is evident that drugs are required in the efficient production of meat, milk and eggs, their indiscriminate use should never be substituted for hygienic management of farm. Drug should be used only when they are required. In addition to veterinary drugs, environmental contaminants that were contaminated in feed, water and air can make residues in animal products. Mycotoxins, heavy metals, pesticides, herbicides and other chemicals derived from industries can be harmful both to animal and human health. Most of organic contaminants, such as dioxin, PCBs and DDT, and metals are persistent in environment and biological organisms and can be accumulated in fat and hard tissues. Some of them are suspected to have endocrine disrupting, carcinogenic, teratogenic, immunodepressive and nervous effects. The governmental agencies concerned make efforts to prevent residue problems; approval of drugs including withdrawal times of each preparation of drugs, establishment of tolerances, guidelines regarding drug use and sanitation enforcement of livestock products. National residue program is conducted to audit the status of the chemical residues in foods. Recently HACCP has been introduced to promote food safety from farm to table by reducing hazardous biological, chemical and physical factors. Animal Production Food Safety Program, Quality Assurance Programs, Food Animal Residue Avoidance Databank are para- or non-governmental activities ensuring food safety. This topic will cover classification and usage or sources of chemical residues, their adverse effects, and chemical residue status of some countries. Issues are expanded to residue detection methodologies, toxicological and pharmacokinetic backgrounds of MRL and withdrawal time establishments, and the importance of non-governmental activities with regard to reducing chemical residues in food.