• 한국환경과학회지
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• 제23권6호
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• pp.1095-1100
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• 2014

Keratin wastes are generated in excess of million tons per year worldwide and biodegradation of keratin by microorganisms possessing keratinase activity can be used as an alternative tool to prevent environmental pollution. For practical use of keratinase, its physicochemical properties should be investigated in detail. In this study, we investigated characteristics of keratinase produced by Xanthomonas sp. P5 which is isolated from rhizospheric soil of soybean. The level of keratinase produced by the strain P5 increased with time and reached its maximum (10.6 U/ml) at 3 days. The production of soluble protein had the same tendency as the production of keratinase. Optimal temperature and pH of keratinase were $40^{\circ}C-45^{\circ}C$ and pH 9, respectively. The enzyme showed broad temperature and pH stabilities. Thermostability profile showed that the enzyme retained 94.6%-100% of the original activity after 1 h treatment at $10^{\circ}C-40^{\circ}C$. After treatment for 1 h at pH 6-10, 89.2%-100% of the activity was remained. At pH 11, 71.6% of the original activity was retained after 1 h treatment. Although the strain P5 did not degrade human hair, it degraded duck feather and chicken feather. These results indicate that keratinase from Xanthomonas sp. P5 could be not only used to upgrade the nutritional value of feather hydrolysate but also useful in situ biodegradation of feather.

• 대한치과보철학회지
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• 제38권2호
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• pp.226-241
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• 2000

Recently a new generation of crown and bridge veneering resins containing submicron glass fillers was introduced. These ultrasmall particle hybrid composite materials distinguish themselves, compared with conventional microfill crown and bridge resins, through improved mechanical properties. It is claimed that these composites are suitable for metal free crowns and even bridges using fiber reinforcement. The purpose of this study was to evaluate the effect of thermal cycling on the tensile strength of the following veneering composites: Artglass(Heraeus Kulzer Co., Wehrheim, Germany), Estonia(Kuraray Co.. Japan), Sculpture(Jeneric Pentron Co., Wallingford, U.S.A.), and Targis(Ivoclar Co., Schaan Liechenstein). According to manufacturer's instructions, rectangular tensile test specimens measuring $1.5{\times}2.0{\times}4.5mm$ were made using a teflon mold. Whole specimens were divided into two groups. One group was dried in a desiccator at $25^{\circ}C$ for 10 days, and another group was subjected to thermal cycling($10,000{\times}$) in water($5/55^{\circ}C$). All test specimens were placed in a universal testing machine and loaded until fracture with a crosshead speed of 0.5mm/min. Weibull analysis and Tukey's test were used to analyze the data. The fracture surfaces of specimens were observed in SEM and the aliphatic C=C absorbance peak of Estenia and Targis resin was analyzed using Fourier transform infrared(FTIR) spectroscopy. Within the limitations imposed in this study, the following conclusions can be drawn: 1. Both in drying condition and thermal cycling condition, the highest tensile strength was observed in Estenia testing group(p<0.05). 2. The strength data were at to single-mode Weibull distribution, and the Weibull modulus of all veneering composite resin specimens increased after thermal cycling treatment. 3. After thermal cycling test, the highest tensile strength was observed in the Estenia group, and the lowest value was observed in the Targis group. The tensile strength values showed the significant differences between each group(p<0.05) 4. The aliphatic C=C absorbance peak of Estonia and Targis resin was decreased after light curing, and there was no distinct change after thermal cycling.

• 한국식품영양과학회지
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• 제22권1호
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• pp.19-26
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• 1993

단식 또는 기초사료를 투여한 성장기 rat 에 우지 또는 들깨유를 매일 일정량 투여하여 2일 간격으로 체중변화와 장기중량, 혈액의 생화학적검사 간조직검사를하여 다음의 결론을 얻었다. 완전 단식rat군(F)과 단식중 우지 (FT)와 들깨유(FP)를 투여한 rat군은 1일 평균 -6.2~-4.0%인 체중감소를 보이고 기초식이군 (B) 또는 기초식이에 우지 (BT)나 들깨유(BP)를 투여한 rat군은 1일 2.3~4.0%의 체중증가를 보였다. F군은 4일만에 모두 아사하였고, FT와 FP군은 6~10일 사이에 모두 아사하였다. 단식에 의한 영향으로 아사직전 이들 rat는 간중량(3.6~4.0g) serum cholesterol(70~73.2mg/㎗), serum triglyceride (6.5~7..5mg/㎗) blood glucose (76-91mg/㎗)의 현저한 감소와 GPT (117.5-186.5u), blood urea nitrogen (38~65mg/㎗)을 대폭 증가하는 특징을 가졌다. 유지시료 불포화도에 따른 영향에서 FP군은 FT군에 비해 약 2일 정도 생존일수의 감축과 serum cholesterol, serum triglyceride, blood urea nitrogen 감소를 보이나 GPT, blood glucose를 약간 증가하였다. BP군은 BT군에 비해 serum cholesterol, triglyceride를 상당히 감소하고 blood urea nitrogen의 근소한 감소와 GPT는 대폭 증가하였다. Blood glucose는 거의 차이가 없었다. 간조직 검사 결과 F군은 아사직전 간실질내 염증 세포 침윤을 보이고 FT, FP군은 유지 시료의 불포화도 차이에 관계없이 아사직전 일부 rat가 염증세포 침윤, 간실질의 염증, 간세포의 손상된 모양이 관찰되었다. 따라서 어떤 목적으로 단식 또는 유지만을 공급하는 무단백질 제한식이를 할 때 극심한 체중감소를 보이고 혈중 cholesterol과 trig1yceride는 크게 낮아지며 간을 포함한 모든 조직의 붕괴의 조짐으로 blood urea nitrogen이 크게 증가되고 그에 따른 간기능저하로 GPT도 크게 상승하고 rat의 경우 4~6일만에 사망하였다. 단식중이거나 혹은 정상식이내 고도 불포화 유지 (들깨유)의 섭취는 포화지방 (우지)에비해 혈중 cholesterol 과 triglyceride를 감소시키는 효과는 있지만 GPT가 유의적으로 증가됨을 볼때 장기간 고도 불포화 유지를 다량 섭취함은 간기능을 저하 시킬 수 있음이 나타났다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권2호
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• pp.191-205
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• 2000

The purpose of this study was undertaken to determine the effects of orthognathic surgery on speech. The hyposis stated herein is that functional behaviors of the dentofacial complex, such as speech production, may be adversely affected by deviations of a structural nature(especially, Class III malocclusion). Twenty adults with Class III malocclusion(13 female and 7 male) were studied preoperative, immediate postoperative and either 6 or 12 months postoperative lateral cephalograms. They had mandibular prognathism and had undergone mandible setback operation. The position of tongue, soft palate(Uvula), hyoid bone, respiratory track width, and pharyngeal depth were assessed on lateral cephalograms with 23 cephalometric variables, ANOVA, Paired t-tests and Pearson's product-moment correlation coefficient tests were used to evalute the operative changes in all cephalometric parameters. A experienced speech and language pathologists performed narrow phonetic transcriptions of tape-recorded words and sentences produced by each of the ninth patients and the recording tapes were analyzed by phonetic computer program(Computerized Speech Lab(CSL) Model 4300BI(U.S.A.)) These judges also recorded their ratings of each patient's overall consonants, hypernasality, hyponasality, and articulation proficiency. The results obtained are as follows; 1. There were significant changes in distance of posterior pharyngeal wall to tongue (TI-TW2, TS-TW3) after the surgery at 6 months postoperatively(each p<0.01 p<0.05). 2. The posterior tongue point(TI, TS, PPT) moved posteriorly after surgery and remained to its changed position at 6 months postoperatively(p<0.05). The displacement of tongue was correlated with the movement of mandibular setback amount(p<0.05). The hyoid bone moved posteriorly superiorly after immediate postoperative period. There was significant changes in hyoid bone movement after immediated postoperative period(p<0.05), but returned to its original position during the follow-up period(p>0.05) 3. The soft palate was displaced posteriorly superiorly after immediated operative period and remained to its changed position at 6 months postoperatively(p<0.05). ANS-PNS-SPT angle increasing, PPU-PPPo distance narrowing was showed after surgery, and remained its appearance 6 months postoperatively(p<0.05). 4. There were significant changes in formant value and squre diagram of vowel sound after the orthognathic surgery and the follow-up period. There were significant changes in /ㅅ/sound and posterior tongue sound. 5. The posterior movement of tongue and the posteriosuperior movement of soft palate was correlated with mandibular setback amount after orthognathic surgery. On the vowel squre diagram, the author found that the place of articulation after operation moved downward, backward, upward. 6. In assessing speech abnormalities, dental occlusion should be considered as a contributing factor. The vast majority of subjects with preoperative misarticulations eliminated or reduced their errors following orthognathic surgery. There was significant difference in speech impovement between pre- and postoperation.

• 대한간호학회지
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• 제4권1호
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• pp.38-49
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• 1974

Presently, the performance level of the college student has received a great deal of attention, particularly in the area of professional education. The problem of under achievement, especially in areas dealing with science and technology, has gone through considerable investigation by numerous Psychologists and Educators. Thus for, however, they have not been successful in determining conclusively the non-intellectual factors involved. The maladjustment problem of these students has been a thorn in the side of nursing education for some time. This topic has been discussed among nursing educators without any tangible results. Furthermore, the fact that the number of students who withdraw from nursing education programs before graduation has increased. This represents a major problem for nursing education. This problem area had increased attention drawn to it on October 1957, when Russia successfully launched to first satellite "Sputnik" into space. Various studies seem to indicate that factors related to over achievement and under.achievement can be found in the motivation of the students. This study is aimed at testing 3 hypotheses which hopefully will lead to a better understanding of the learning activities of nursing students and to determine some of their nonintellectually personality traits. Hypothesis I: learning activities in nursing students and persona1ity are correlated, there will be significant differences in personality need structures between 4 classes of nursing collegiate students. Sub-hypothesis: There will also be significant differences in the degree of student satisfaction in her major subject. Hypothesis I: If there is a special personality need structure which is required for the clinical learning activity in general, then there will be significant differences between the personality need structures of under-achievers and overachiever. Hypothesis II : If each clinical nursing subject requires different personality need structures, then there will be differences in personality need structure between the different clinical groups Methodology: 1. Tool: A Korean translation and correction of the Edwards Personal Preference Schedule of U.S.A. was used. 2. Subject and Test Method: Subjects were nursing students at Yonsei University, who enrolled for Fall semester of 1971. The Researcher herself executed the test for the test for the class as a group, and the absent students were tested indidually. Out of 307 students, 293 students (95.4%) were reported. 3. Statistical treatment: The mean and standard deviation for each of the 15 personality need variables were computed and the value of T-test was obtained to determine the differences in the personality need structures between each group. Results: 1, For the first hypothesis, the personality need structures between each of the 4 classes and the reported degree of satisfaction in major subject showed significant differences. Therefore the hypothesis I was accepted. 2. The comparison of personality need structure of under-achievers and over-achievers in clinical fields showed significant differences. Thus hypothesis II was accepted. 3. Personality need structure between clinical subject groups showed significant differences therefore the 3rd hypothesis was accepted.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 춘계학술대회
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• pp.777-780
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• 2015

현재 우리나라 농업은 농식품 산업과 ICT 융합화로 새로운 가치를 창출하고, 농촌 지역 정보화 확충, 농정 시스템 효율성 제고 등을 통해 성장동력을 확충함으로써 지속가능한 성장을 도모하고 있다. 한편 국내 농업 ICT 융합 기술은 생산 분야 위주로 초기단계 수준에 머물러 있어, 생산 유통 소비단계를 아우르는 체계적인 기술개발과 표준화를 통한 성공 모델의 확산이 필요하다. 또한, 대형 유리 온실의 관제 및 제어 시스템은 외산 제품이 대부분이고, 농식품 ICT 융복합 기술에 관한 표준화 미흡 및 관련 기업의 영세성 등으로 민간 주도의 농식품 ICT 융복합 활성화에 한계가 있다. 그리고 기존의 농업기술에 정보화기술, 자동제어 기술 등 ICT 고유의 기술을 융합시켜 농업의 생산 유통 소비 전 과정에 걸쳐 생산성향상, 효율성 증대, 품질향상 등과 같은 고부가가치를 창출 방안 모색이 필요하다. 따라서 본 논문에서는 국내 농업-ICT 융합 기술 개발 현황, 표준화 동향 및 정책 동향 등을 분석하여 우리나라가 선도할 농업 ICT-융합 기술 분야를 도출하고 향후 표준화 방안을 제시하고자 한다.

• 재무관리연구
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• 제24권2호
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• pp.81-111
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• 2007

본 연구는 외환위기 회복 이후기간을 대상으로 경영자 유인이 자본구조에 미치는 영향을 분석하기 위하여 소유경영자지분율과 레버리지비율간의 관계를 패널자료분석법을 이용하여 검증하였다. 연구결과는 첫째, 전체기간분석에서 소유경영자지분율수준이 58.48%까지는 지분율의 증가에 따라 레버리지비율이 감소하고, 그 이상의 지분율 수준에서는 소유경영자지분율의 증가에 따라 레버리지비율이 증가하는 U자(字)형 곡선관계가 존재한다는 것을 확인하였다. 둘째, 하위기간으로 구분하여 분석한 결과에서 [하위기간 1]에서는 소유경영자지분율과 자본구조간에는 역(逆) N형 비선형 관계가 존재한다는 것을 확인할 수 있었다. 소유경영자지분율이 낮을 때는 소유경영자지분율의 증가에 따라 레버리지수준이 감소하고, 경영자 안주현상이 발생할 수 있는 지분율 수준에서는 소유경영자지분율의 증가에 따라 레버리지비율의 증가현상이, 그 이상의 지분율수준에서는 다시 레버리지비율이 감소하여 본 연구의 가설을 지지하는 결과를 얻을 수 있었다. [하위기간 2]에서는 소유경영자지분율 수준이 증가할수록 레버리지 수준이 높아지는 결과를 보였다. 이는 정부의 레버리지 축소정책이 어느 정도 완화되면서 경영자는 부채를 증가시킴으로써 향유할 수 있는 이익을 최대화하고자 하는 유인이 강하게 나타난 것으로 이해할 수 있었다. 이러한 연구결과로부터 기업들은 레버리지로 인하여 파산위험, 재무적 곤경 현상, 경영자 자신의 고용위험 등과 같이 위험 부담이 많이 증가하는 경우에는 상당한 수준의 지분율 범위까지 레버리지를 감소시키고자 하는 유인을 갖는다는 것을 알 수 있었다. 그러나 재무위험에 대한 부담이 어느 정도 완화되는 경우에는 레버리지효과를 향유하고자 하는 유인이 강해진다는 것을 확인할 수 있었다.

• Investigative Magnetic Resonance Imaging
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• 제20권3호
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• pp.158-166
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• 2016

Purpose: To understand clinical significance of irregular interface between meningioma and adjacent brain parenchyma in predicting histological grading of tumor, focusing on brain parenchymal invasion. Materials and Methods: Pathologically confirmed 79 cases with meningiomas with pathological reports about the presence of parenchymal invasion were included. We defined the presence of interface irregularity as either spiculations or fuzzy margins between the tumor and brain parenchyma. We counted number of spiculations and measured ratio of fuzzy margin length to whole length of mass with consensus of two neuroradiologists. We classified the patients into Present group and Absent group, and the two groups were compared by using the Mann-Whitney U test. Statistical correlations between the presence of an interface irregularity and brain parenchymal invasion by the tumor as well as meningioma histological grade were tested with chi-square test. The optimal cutoff values of spiculation numbers and the ratio of fuzzy margins were determined. The sensitivity and specificity of number of spiculations, ratio of fuzzy margin and the presence of irregular interface as combined parameters for predicting the parenchymal invasion were calculated using ROC curve analysis. Results: Statistically significant differences were noted between the Present and Absent groups for number of spiculations and ratio of fuzzy margin (P = 0.038 and P = 0.028, respectively). The optimal cutoff value for number of spiculations (> 4.5 with 61.1% sensitivity and 68.9% specificity) and the ratio of fuzzy margin (> 0.24 with 66.7% sensitivity and 65.6% specificity) were determined. The sensitivity and specificity of interface irregularity as the combined parameters were 72% and 59%, respectively. The interface irregularity between tumor and brain parenchyma significantly correlated with not only brain parenchymal invasion (P = 0.001) and but also histological grade (P < 0.001). Conclusion: The interface irregularity between tumor and brain parenchyma in MRI can be a strong predictive factor for brain parenchymal invasion and high grade meningioma.

• 한국콘텐츠학회논문지
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• 제12권5호
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• pp.103-112
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• 2012

본 연구는 과학대중화에 있어 중요한 역할을 수행하고 있는 국내 과학전문채널인 'YTN 사이언스'가 시청률, 콘텐츠, 제작비의 부족을 드러내고 있다는 문제인식 하에, 우선 현행 국내 과학전문채널의 프로그램 편성과 운영현황, 홍보 전략을 탐색적으로 확인하였다. 다음으로 미국(디스커버리 채널, 내셔널지오그래픽 채널), 영국(BBC Knowledge), 일본(사이언스채널), 중국(CCTV 10) 등 해외 각국의 과학방송채널 특히, 중요 프로그램들을 분석하여 향후 국내 과학전문채널에 활용 및 접목시킬 수 있는 가능성을 모색하였다. 이러한 현실진단과 해외사례분석을 통해 다양한 시사점을 확인하였으며, 이를 통해 제시될 수 있는 콘텐츠 개발 및 홍보전략은 다음과 같다. 우선 콘텐츠가치 제고를 위한 편성전략의 수정이 필요한 바, 타깃 시청집단과 시청자 라이프스타일을 고려한 편성 재조정, 줄띠편성(Stripping)을 통한 시청습관화 전략, 프라임타임(prime time)대의 전략 프로그램 배치가 필요할 것이다. 다음으로 콘텐츠제작 및 활용전략 측면에서는 콘텐츠 제작의 이중적 전략(지식전달, 흥미전달의 두 분야로의 구분), 프로그램의 대표 캐릭터의 기획과 활용, 한국적 과학기술소재의 선택, SNS와의 전략적 연계, 소재의 다변화와 심층화, OSMU 활성화 전략이 요구될 것이다. 마지막으로 홍보전략 차원에서는 과학관련 행사 개최와 중계방송을 통한 채널 인지도 제고, 잡지 및 단행본 발간 등 인쇄매체로의 확장을 통한 홍보전략 수행, 온라인/모바일 홍보 전략의 강화 등을 제시할 수 있겠다.

• 대한의생명과학회지
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• 제12권3호
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• pp.153-160
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• 2006

Human colon cancer is the second most fatal disease among a variety of cancers to cause cancer death in U.S.A. and its incidence rate is currently increased in Korea. Recently, many studies have been being progressed on the efficacy of diverse combination treatments. But results of these studies in vitro were not similar those in vivo. This study compared the anticancer reactions between each use of arsenic trioxide and taxol against human colon cancer HT-29 cell line and combined use of two drugs. And these results compared with the results of HT-29 spheroid cells having similar characteristics to the solid tumor in vivo. The spheroid of HT-29 cells was formed by using a multicellular spheroid system and the result was observed through electron microscopy. In vitro cytotoxicity of each use of arsenic trioxide and taxol was evaluated in HT-29 monolayer cells. The $IC_{50}$ value for arsenic trioxide was to be $33{\mu}M$ and taxol was to be 18nM. The result treated with the combination of taxol and arsenic trioxide decreased the cytotoxicity on the HT-29 monolayer cells. The spheroid cells represented higher resistance against drugs than the monolayer cells. I demonstrated DNA fragmentation after incubation with concentrations more than $10{\mu}M$ arsenic trioxide and 100nM taxol for 48h, on the monolayer cells. But the results of HT-29 cell line treated with the combination of taxol and arsenic trioxide was the same as the outcome of control samples that were not treated with any drug. And I don't demonstrated DNA fragmentation on the spheroid cells. These results suggest that apoptosis was not induced in the use of the combination can be thought as that arsenic trioxide might work as an antagonist to inhibit a taxol mechanism to induce apoptosis. And the spheroid cells represented higher resistance against drugs than the monolayer cells.