• Bulletin of the Korean Chemical Society
• /
• 제26권9호
• /
• pp.1335-1338
• /
• 2005

Thianthrene cation radical perchlorate ($Th^{+{{\cdot}}}{ClO_4}^-$) reacted readily with two isomeric thiols, benzylthiol (1) and 4-methylbenzenethiol (7) in an acetonitrile solution at room temperature. From the reaction of 1, the major products, N-benzylacetamide (4) and benzyl sulfide (5), are characteristic of benzyl carbocations while the minor one, benzyl disulfide (6) implies free radical component of the reaction. It is unprecedented that the formation of a benzyl carbocation was caused by the extrusion of sulfur atoms from benzyl sulfur cations (3). In contrast, from the reaction of 7, only p-tolyl disulfide (10) was obtained from both sulfur radicals and cations. In the reaction of 7 the thio-extrusion was not observed from the p-tolyl sulfur cation (9). A thianthrene cation radical ($Th^{+{{\cdot}}}$) was reduced quantitatively to thianthrene (Th) in both reactions.

• Nutrition Research and Practice
• /
• 제16권3호
• /
• pp.405-417
• /
• 2022

BACKGROUND/OBJECTIVES: This study examined the changes in food behaviors of dietary fatty acids over 2007-2018 among Korean adults. SUBJECTS/METHODS: This study used data from the 4th (2007-2009), 5th (2010-2012), 6th (2013-2015), and 7th (2016-2018) Korea National Health and Nutrition Examination Surveys. A total of 46,307 adults aged 19-64 yrs were selected and dietary data were obtained from a single 24-h recall. In the 4th and 7th data, the major food sources for each fatty acid based on the contributing percentage of the food item were compared. The consumption trends in the major food sources were presented as grams per day over 2007-2018 and compared across the survey periods using the multiple regression model. RESULTS: From 2007 to 2018, for total fat, saturated fatty acid (SFA), and monounsaturated fatty acid, the contribution of animal food sources, including beef, chicken, and eggs increased but plant food sources (e.g., tofu, soybean, and plant oil) decreased. As polyunsaturated fatty acid sources, mayonnaise, eggs, and bread showed higher contributions, whereas soybean and tofu showed lower contributions in the 7th data compared to the 4th data. For n-3 fatty acids, the contribution of fish decreased between the 4th and 7th data. Over 12 yrs, the significant increases in the absolute amount of consumption from animal sources were observed. In contrast, decreases in the consumption from plant sources and fish were seen across the survey periods. CONCLUSIONS: In Korean adults, increases in the intake of dietary fatty acids along with changes in the food behaviors during 2007-2018 have evoked great concern for SFA intake, which is a cardiovascular disease risk factor. Healthy food sources of dietary fatty acids should be emphasized in this population.

• 한국초지조사료학회지
• /
• 제36권1호
• /
• pp.1-6
• /
• 2016

2014/2015년도 전국 동계사료작물, 특히 벼 입모 중 파종했던 이탈리안 라이그라스의 월동 후 생육 상황은 매우 저조했다. 이탈리안 라이그라스의 생육저해 요인을 찾기 위해 충남 논산지역의 생육상황과 인근 대전지역의 기상을 분석한 결과는 다음과 같다. 월동 후인 2015년 2월 8일과 9일의 최저기온과 최대순간풍속은 각각 $-8.8^{\circ}C$와 10.7 m/s, $-12.4^{\circ}C$와 9.6 m/s로서 소낙눈을 동반한 강풍이 불면서 온도도 매우 낮았는데, 이는 토양 과습으로 토양 표면에 노출되어 있던 이탈리안 라이그라스의 뿌리 생장에 매우 불리하게 작용하였다. 연이어 2월 12, 13, 14일에도 각각 $-4.1^{\circ}C$와 11.6 m/s, $-5.6^{\circ}C$와 10.3 m/s, $-4.7^{\circ}C$와 7.5 m/s의 저온과 강풍피해를 받았다. 더욱이 1월부터 지속된 가뭄현상으로 건조상태가 지속되다가 2월 15, 16일에 19 mm의 강우가 내렸으나 생육을 회복하기엔 역부족이었다. 2월 26, 27, 28일에도 $-1.8^{\circ}C$와 13.7 m/s, $-3.5^{\circ}C$와 10.6 m/s, $-4.1^{\circ}C$와 6.8 m/s의 저온과 강풍피해가 있었다. 3월 3일까지 고사개체가 59% 이상으로 많았으며 3월 4일부터 12일까지 9일간의 저온과 강풍은 이탈리안 라이그라스를 생육 회복불능상태로 몰고 갔다. 따라서 2014/2015년의 이탈리안 라이그라스 수량감소의 주원인은 다음과 같이 분석되었다. 2014년 10월, 11월의 강우로 인하여 벼 수확 후 볏짚수거가 지연되어 볏짚 밑에 눌려 연약하게 자란 개체가 월동 후 저온에 고사되었다. 배수로 미설치로 논 토양 표면의 수분이 과다하여 뿌리를 땅속으로 내리지 못한 채 월동하게 된 이탈리안 라이그라스가 봄에 서릿발 및 가뭄과 강풍을 동반한 저온피해를 받아 뿌리가 말라버려 작물이 고사되어 버리는 상황이 발생되었다.

• 한국환경교육학회지:환경교육
• /
• 제17권1호
• /
• pp.77-89
• /
• 2004

This study aims to consider interrelations and reasonability to inquiry elements of environment units in 10th Science textbooks of 7th curriculum on the basis of their inquiry contexts, processes and activities. Frequency of inquiry contexts is 59.9% of the highest value in natural environment context but is 4.0% of the lowest one in techno-industrial context. Measurements, inferences, predictions, experiments, data-interpretations, correlations, conclusionreveals in inquiries are in all the textbooks, but observations and classifications, hypothesis generations, controlling variables, experimental designs and generalizations are not in some textbooks. Discussions, experiments, investigations in inquiry activities are included in all the textbooks. However, inspections are not appeared in the all the books. Based on the above results, social and techno-industrial inquiry contexts in the varied scopes are necessary in the environment curricula with a unified direction. Inquiry processes with pro-environmental behaviors as a last goal might be given into the curricula, having tasks that could be understand unified inquiries. In addition, inspections with effectiveness might be thrown into the scene of education.

• 대한약리학회지
• /
• 제28권1호
• /
• pp.11-18
• /
• 1992

Physostigmine을 급성(0.75 mg/kg), 7일간 매일 1회(0.75 mg/kg) 그리고 7일간 연속(0.15 mg/kg/h) 투여한 쥐의 선조체에 있어서 dopamine(DA) 및 대사체와 tyrosine hydroxylase(TH)활성도의 변화를 검색하였다. 급성 투여 1시간 후 선조체의 DA 농도는 변화가 없었으나 dihydroxy-phenylacetic acid(DOPAC)과 homovanillic acid(HVA)농도는 증가하였다. 또한 DA의 turnover의 증가를 제시하는 DOPAC/DA와 HVA/DA의 비율도 증가하였다. 그러나 TH활성도는 24시간 후 감소를 나타내었다. Physostigmine을 매일 및 연속 투여군에서는 DA과 대사체의 농도에는 변화가 없었으나, DA의 turnover의 감소를 제시하는 DA과 대사체의 비율은 감소하였다. 그러나 TH활성도는 매일 투여군에서만 감소를 나타내었다. 이러한 결과는 physostigmine을 급성 및 아급성으로 투여시 dopamine대사의 변화가 있음을 제시한다. 또한 콜린 신경계의 아급성 자극은 dopamine 대사 및 활성도를 감소 시킬 가능성을 시사해 주었다.

• 대한치과보철학회지
• /
• 제44권4호
• /
• pp.432-442
• /
• 2006

Statement of problem: One of common problems associated with dental implant is the loosening of abutment screws that retain the implants. Purpose : This study was performed to investigate the influence of abutment screw length and repeated tightening on screw loosening in dental implant. Material and method: Forty nine Hexplants (13mm length, 4.3mm diameter, Ti grade IV, Warantec. Co. Ltd. Seongnam, Korea) and cementation type abutments(straight abutment) and abutment screws (0.4mm/pitch) were divided into 7 groups, depending on abutment screw length. Each implant and abutment was tightened to 30Ncm by torque controller(MGT50, MARK-10 Inc., USA) and the removal torque values were measured during 10 consecutive closure/opening trials. Results and Conclusion: The results of comparing the removal torque value are as follows : 1. There is no significant difference in the removal torque value between groups in 10 consecutive closure/opening trials (p = 0.97). 2. If the fractured abutment screw is engaged in longer than 2.425 thread length, there is no significant difference in the preload between the fractured abutment screw and the new abutment screw when both are equally tightened to 30 Ncm. 3. The removal torque value in the 1st trial(24.510 Ncm) was lower than that in the 2nd, 3rd, 4th, 5th, 6th, 7th trials and the removal torque value in the 2nd trials(25.551 Ncm) was maximum and was decreased in 1311owing trials. The removal torque value in the 1st trial was significantly lower than that in the 2nd, 3rd, 4th trials and was significantly higher than that in the 8th, 9th, l0th trials(p<0.05). 4. In the 2nd, 3rd, 4th, 5th, 6th, 7th trials, the abutment screw was mainly influenced by settling effect and the higher preload was obtained In the 8th, 9th, l0th trials, the abutment screw was mainly influenced by adhesive wear and the progressively lower preload was obtained.

• 한국학교ㆍ지역보건교육학회지
• /
• 제2권2호
• /
• pp.39-55
• /
• 2001

The purpose of this study was to provide the necessary fundamental data in composing a systematic text content of the public health by analyzing each text, domain, and teaching contents suggested in the textbooks as well as teachers' guides of the 7th elementary school education curriculum, while the study subjects were as follows. 1. The health education content suggested in the 7th physical education curriculum were analyzed and examined. 2. The health teaching content of each textbook in the 7th elementary school curriculum was to be analyzed and examined. In order to resolve the above research issues, the physical, spiritual, and social domain along with the (1) Proper living habit, (2) Health and nutrition, (3) Sex education, (4) Prevention of the sense-organic diseases, (5) Cleanliness of food, (6) Oral hygiene, (7) Individual health and public health, (8) Safety in living, (9) Abuse and usage of medication, educational content suggested in the 7tand (10) Environment pollution focused around the health of the elementary school education curriculum was analyzed and its outcome was as below First, compared with the 6th elementary school education curriculum, the health content suggested in the 7th elementary school education curriculum was decreased. Second, although each grade's teaching content of the health domain in the physical education was considered in its structure following after the according systems, they were preponderant in partial subjects such as the safety in living, nutrition, proper living habit, sport, and health in sport. oo. Third, the health education content was organized in 4 units such as the physical growth and development, prevention of diseases, safe living, and leisure living(leisure, spiritual health, and etc.) for the 3rd and 4th grade. Then, as for 5th and 6th grade, it was organized in 3 units such as the understanding the human body, prevention of disease, and leisure and safe living. Fourth, in the physical educational health domain, a strong point was constructed within the physical, spiritual, and social areas of the elementary school physical education. Fifth, the number of the public health education contents directly related with the health education was 43 as with 25 indirect contents. Sixth, each grade's domain unit structure of the public health content was heavy upon the physical and social area throughout every grade while in opposite, the spiritual domain' s unit structure was weak. In according to each grade, the physical domain was stressed in 4, 5, and 6 grades while the social domain was stressed in 1, 5, and 6 grades.

• 한국가족관계학회지
• /
• 제23권1호
• /
• pp.75-95
• /
• 2018

Objectives: This study aims to examine a school adjustment trajectory of adolescents from continued single parent families and its associated factors by comparing it to that of adolescents of two-parent families. Methods: We selected 4th grade students from Korean Youth & Youth Panel Survey (KCYPS). Using a multi-level growth modeling, we followed the trajectory of school adjustment until 9th grade and the effects of family income, parenting styles, and academic motivations of adolescents on the intercepts and the slopes. Results: Adolescents' school adjustment were decreased from 4th grade to 7th grade and then increased from 7th to 9th grade. The adolescents of continued single parent families showed a lower school adjustment than those of two parent families and this trend remained constant during the period. The effects of family income, parenting style, and academic motivation were confirmed to explain the gap between the adolescents of single parent and two parent families. Conclusions: The results imply that an earlier intervention is necessary to reduce the gap. We need to offer income support and decent quality of work for single parent family to reduce the economic hardship and also provide parental education that is designed to enhance academic expectations and motivations.

• 한국지구과학회지
• /
• 제22권3호
• /
• pp.248-257
• /
• 2001

7차 과학과 교육과정은 인간중심 교육철학이 도입되었다는 특성을 갖고 있다. 인간중심 교육과정은 학문중심교육과정보다 학습자의 경험을 강조하는 학습자 중심의 교육을 표방하고 있다. 본 연구에서는 우리 나라 과학과 교육과정의 개편 과정에 표출된 배경, 성격 그리고 목표에서 7차 과학과 교육과정의 의의를 찾고 그 과제와 전망을 논의하였다. 7차 과학 교육과정은 학습자의 경험을 강조하는 인간중심 교육과정으로서 구체적인 교육활동이 실생활 소재로 이루어져서 적용되어야함을 강조하고 있다. 이에 관련된 성과를 위해서는 현대과학이 가지는 사회적인 요소를 고려한 과학의 본성에 대한 교사교육이 필요하며, 실생활 맥락을 교육적이고 인식론적인 관점에서 연구하여 과학과 일상생활 맥락의 차이에 대한 적절한 교육적 구명이 요청된다.

• 한국수학교육학회지시리즈C:초등수학교육
• /
• 제9권2호
• /
• pp.119-134
• /
• 2005

The goals of this study is to analyze develop the materials which help students develop spatial sense in elementary school and to investigate its effects. To accomplish those goals, the 7th National Curriculum was analyzed to identify the contents of spatial sense. After analyzing the 7th National Curriculum, the principle for developing the teaching aids focusing the realization of the contents in the spatial sense was set up. And then various teaching materials which can enhance students' spatial sense was developed. It is consist of 17 kinds of concretely operating materials, 7 kinds of tangram papers, one web-material. To verify the effect of the materials, surveyed the usability of the materials and two classes was selected and tests were administered before and after the treatment. Through this application, several conclusion were drawn. First, a survey result says that teachers thought materials developed would be effective in developing spatial sense. Second, the materials developed were effective to develop spatial sense. The score gained by the experiment group after the treatment was statistically meaningfully higher than the control group. This means that the materials developed helped children to develop spatial sense.