衛生昆蟲에 대한 無公害農藥(昆蟲發育沮害劑)의 殺蟲機作 및 應用技術開發硏究

金正和,李炯來,李仁煥,李容揆,崔鐘錫 충북대학교 농업과학기술연구소 1993 農業科學硏究 Vol.10 No.2

In recently, much pesticides were used for control of agricultural and medical insects. The result of using pesticides were social problem because of environmental pollutions with pesticides in urban and farm village. The environmental pollutions were very serious. This experiment was conducted to eluciated of reduce to environmental pollution bring about using pesticides (organophosphates, carbamates, pyrethroids, and insect growth regulators) for control of medical insects(house fly, Musca domestica L and mosquito, culex pipiens pallens copuillett) and carried out the method of pest control. And the result are summarized as follows. The Kyongbuk house fly strain treated with pyriproxyfen on third instar larvae were very high mortality and low emergence. When use it, at the same time, we can reduce degree of environ-mental pollution and house fly populations. Using of imidan was effective in Seoul and Chungnam house fly strains. In mosquito larvae, the efficacy of icon to chungbuk strain, propoxur to Chungnam and Chungbuk strain, imidan to Kyongbuk strain, fenthion to Chungnam strain were excellent. In result of spraying imidan and icon on adult mosquitoes, the efficacy of icon was excellent than imidan. In esterase electrophoresis, third instar larvae of Chungnam house fly strain fed on artificial diet mixed with pyriproxyfen LC50 were very high activity of -Est-αl in early stage(second day after third instar larvae fed on diet), and the activity of Est-αl was very strong in late stage(se-vents day after third instar larvae fed on diet). In Kyongbuk strain, -Est-αl and Est-αl were detected in early and late stage, and activities of and -Est-αl and Est-αl were detected almost equally in late stage. It was very characteristic in this experiment. Third instar larvae fed on diet mixed with pyriproxyfen LC95 were detected -Est-αl and Est-αl almost equally. It was believed moulting control in insects. In electrophoresis with head, thorax, abdomen of house fly adult, -Est-α2 -Est-αl, Est-αl, Est-α2, Est-α3 were detected in abdomen in susceptible strain and only -Est-αl, was net detected in thorax -Est-αl, was detected in head, thorax and abdomen of Chungbuk strain and -Est-αl was detected in head, -Est-α2 in thorax of same strain. Activities of chitinase in late instar larvae of house flies fed on artificial diet mixed with pyrip-roxyfen LC50 and LC95, in pyriproxyfen LC95, analysised low and high again with the lapse of time in Kyongbuk strain. This was believed that the activity of chitinase was became high just before emergence. The result of filter paper test with mosquitoes were very high index(265) of esterase activity in Chungnam strain among all mosquito strains. In this reason, we can suppose that used pyrip-roxyfen (IGR) in Chungnam area for control pest. In this reason, it was more reasonable made use of pyriproxyfen than other pesticide in Chungnam area.

In₆S₇ nanoparticle-embedded and sulfur and nitrogen co-doped microporous carbons derived from In(tdc)₂ metal-organic framework

Choi, In-Hwan,Jang, So-Young,Kim, Hyun-Chul,Huh, Seong The Royal Society of Chemistry 2018 Dalton Transactions Vol.47 No.4

<P>Indium sulfide nanoparticle (NP)-embedded microporous carbons co-doped with S- and N-dopants are easily prepared by a direct carbonization of the as-prepared In(iii)-based metal-organic framework (In-MOF), [Et2NH2][In(tdc)2]·DEF, containing ditopic S-containing 2,5-thiophenedicarboxylate (tdc<SUP>2−</SUP>) bridging linkers as a potential source of S-dopant. The charge on the anionic framework of [In(tdc)2]<SUP>−</SUP> is balanced by Et2NH2<SUP>+</SUP>, which is also a potential N-dopant. Simultaneous embedding of In-based NPs, S-, and N-co-doping is achieved in a simple single step carbonization of In-MOF. Three porous carbon materials (PCMs), PCM-700, PCM-800, and PCM-900, are obtained from the carbonization of In-MOF at 700, 800, and 900 °C, respectively. The gas sorption analysis indicates them as good CO2 sorbents. The photocatalytic degradation of methyl orange by PCMs under visible light irradiation is also effectively operable owing to the photocatalytically active semiconducting indium sulfide NP with a small bandgap. The main component of indium sulfide NPs is revealed as In6S7 based on the powder X-ray diffraction pattern. Small amounts of metallic In and In2S3 are also observed. The specific capacitances of PCMs are also estimated from the galvanostatic charge/discharge curves. PCM-900 exhibits the highest gravimetric specific capacitance of 99.0 F g<SUP>−1</SUP> at a current density of 0.05 A g<SUP>−1</SUP>.</P>

청계산 청계사의 역사와 위상

황인규(Hwan In-gyu) 보조사상연구원 2013 보조사상 Vol.39 No.-

본고는 의왕시 청계사의 역사와 그 위상을 천착한 연구이다. 청계산 청계사는 고려 원간섭기 역관출신 趙仁規가문의 원당이 되면서 사세가 크게 부각되었다. 조인규 가문 출신의 천태종계 승려들은 과천 청계사와 수원 만의사 일대에서 활동하였을 뿐만 아니라 여말선초 불교계를 주도하게 되는 무학자초와 그의 제자 철호조선이 주지에 재임하였다. 조선초 과천의 資福寺로서 지정되었으며, 圓通菴은 산내 암자였던 듯하다. 乖崖金守溫의 「圓通菴重創記」기문에 의하면 1425년(세종 7) 승려 海幢이 원통암을 세종의 비 昭憲王后의 시주를 받아 1428년(세종 10) 佛殿3칸과 禪僧兩堂등을 중창하였다. 왕후의 8남 永膺大君이 前龍門寺주지 戒眼과 문도들로 하여금 9년간 주재하여 보수 중창되었다. 청계사는 세종말년에서 단종대 초에 태종의 2녀 경정공주와 태종 2남 효령대군, 세종의 장모 삼한국 대부인 안씨 등이 주지 覺頓과 함께 『화엄경』 1,470판으로 인출하여 雜華殿을 짓고 봉안하였다. 이는 고려 대각국사 의천이 가져온 『華嚴經疏鈔』이 유실되어 없어진 것을 청계사에서 개판하였던 것이다. 이렇듯 청계산의 산내암자인 원통암은 세종의 비 소헌왕후와 8남 영응대군의 원당이었으며, 소헌왕후의 5남 광평대군과 7남 평원대군을 비롯하여 1445년(세종 27) 4월 삼한국 대부인 안씨 등과 함께 청계사에 머물며 독경하는 등 왕실의 관심이 컸다. 고려 대각국사 의천이 가져온 『華嚴經疏鈔』가 그 이후 세종대 당시까지 유실되어 찾아볼 수 없었는데, 이를 바로 청계사에서 개판하였던 것이다. 이렇듯 청계사는 산내암자 원통사(암)과 더불어 조선초 왕실의 주목을 받은 원당이었다. 청계사는 연산군대 선교양종의 본산이 폐치되자 명종대 허응보우가 선교양종을 복립할 때까지 선교양종을 아우르는 선종의 본산이었다. 광해군대 세자의 원당이 되었으며, 고승 벽암각성과 고한희언이 주석하며 재를 올리는 등 왕실의 원당이었다. 그런 한편 조인규가문에서도 청계사의 사적비를 짓는 등 조선후기에도 원당으로서의 위상을 지녔으며, 정종의 의해 왕실의 원당이 되었다. 즉, 정조는 잠저시 인근의 화성 용주사에 앞서 청계사를 願堂으로 삼았다. 1789년(정조 13) 아버지 사도세자의 능침인 현융원에 행차시 청계사에 들려 顯隆園祭閣을 세우고 매년 두 차례 제사를 드렸다. 그리고 철종대 근대불교를 중흥하게 되는 경허선사의 출가처가 청계사였다. This paper examines the history and the status of CheonggyesaTempleinUiwang. The temple was highlighted as a votive shrine by the family of Ingyu Cho, an interpreter in the occupation period of Yuan. The tien-tai monks from the family performed their activities at the Gwacheon Cheonggyesa temple and at the Suwon Manuisa temple. Then, Muhakjacho and his discipline, Cheonhojoseon, who led the Buddhism community from the end of the Goryeo to the early Joseon period, became head abbots. The Cheonggyesa temple was designated as a jaboksa; further, the wontongam became a hermitage in the mountains. The Wontongam Jungchanggi, written by Seungae Suwon Kim, stated that the Buddhist monk Haedong received an order from Empress Soheon, wife of King Sejong in 1425 (7th year of King Sejong). Following her order, he built 3 Buddhist sanctums and the Seonseungyangdang in 1428 (10th year of King Sejong). Yeongeungdaegun, the 8th youngest son of the empress, ordered Gyean, the head abbot of the jeonryongmunsa temple, and his disciplines to stay at the temple for 9 years in order to repair and establish the temple. The Cheonggyesa temple was tributed by establishing the japhwajeon from 1,470 sheets of Hwaeomgyeong with Princess Gyeongjeong, the second daughter of King Taejong, Hyoryeongdaegun, the second son of the king and Mrs. Ahn, mother- in-law of King Sejong, by the head abbot Gaksun. This means that the temple re-established the Hwaeomgyeongsocho brought by Daegakguksa Uicheon but lost. The Wontongam, a shrine in Mt. Cheonggye, was avotiveshrine of Empress Soheonand Yeongeungdaegun aswellas that of Gwangpyeongdaegun and Pyeongwondaegun, the 5thand 7thsons of King Sejong.The Cheonggyesa temple became the head abbot of both Buddhismfaiths until Heoeungbou restored the faiths in the era of King Myeongjong after the head abbot of the faiths were closed in the era of Yeonsangun. The temple became a votive shrine for princes in the Gwanghaegun era; it was also the royal votive shrine where prominent Buddhist monks of Byeokamgakseong and Gohanhuieon paid tributes. Meanwhile, the family of Ingyu Cho established a sajeokbi (stele for commemoration), which had the status of a votive shrine; it later became the royal votive shrine by King Jeongjong. During his evacuation, the king designated Cheonggyesa temple as the votive shrine prior to the Yongjusa temple near Hwaseong. In 1789 (13th year of King Jeongjo), the king visited Cheonggyesa temple on the way to Hyeonyungwon, the tomb of his father, and established the Hyeonyungwon Jegak, holding ritual ceremonies twice a year. The Cheonggyesa temple was where Gyeongheoseonsa, who revived modern Buddhism during the era of King Cheoljong, entered Buddhist priesthood.

동아시아 문학교육의 전통

김인환 한국문학교육학회 2000 문학교육학 Vol.6 No.-

The literary critics and philosophers of East-asia believed the being of beings that is tao, tathagata and li. Their stable attitudes come from belief on the universal truth. Everyone who lived in the East-asian world had the universal textbook which was valid to all creatures before 19th century. Wonhyo thought that saddarma pundarika sutra must be a best textbook of all mankind. he analyzed the structure, content and style of that sutra. Toege recommended close reading to his disciples. He apprehended the whole content of text first, and then analyzed every part of text next. He also took account of parts when he grasped the meaning in its totality and vice versa. He always thought non controversial being would be more important than controversial beings. Yonam compared the art of writing with the art of war. Like soldier who exercises to march in file, to attack and to defend, writer has to collect, arrange and compose materials unceasingly. Every writer has to make his writings fresh and rare by interrelating texture and structure like a general who has to make his soldiers active by interrelating concrete conditions in detail and whole situation. Zeami searched for flower which symbolizes uppermost enlightenment in his education of drama. Education of drama is not only problem of technique but also problem of mind for him. He who wants to be an actor has to do penance to make his own flower of enlightenment bloom in his inner mind. If someone wants to perform his part with brilliance, he should open his inner eyes. Reality(monomane) would be one of minimum essentials to education of drama. But good actors are supposed to master grace from natural experience. The flower means the egolessness state of mind. It needs docta ignorantia in other words "don't know mind". To study literary education of East-asia, mutual cooperations in the East-asian level will be an unavoidable necessity for scholars and teachers to collect and arrange the data. Unfortunately, there have not been productive dialogues on this issue among the scholars and teachers in the field, and this resulted in the lack of interdisciplinary joint work in literary education of East-asia. We regard not only universality of East-asia but also differences of individual unit of East-asia as of great importance. There have been many articles which mix Zhu Xi with Yulkok. What is the difference between Zhu Xi and Yulkok? There are many scholars who cannot answer this question. The scholars who do not take a context of East-asian culture into consideration cannot make a distinction between creative idea and imitation. We do not want to rationalize particular phase of literary education in Korea through isolated nationalistic point of view but to contribute to making rich the method and scope of literary education in East-asia through its concrete research.

理論的 用語를 土台로한 國民學校 算數科 學習資料 開發에 關한 硏究

梁仁煥,朴根生,黃秉德 淸州大學校 科學敎育硏究所 1977 淸州大學校 科學敎育硏究所 Vol.2 No.-

This research study is aimed more at pursuing the methods of promoting logical thinking to be debated in the present-day mathematical instruction, searching to discover the foundation underlying it, and then at meterializing even more learning effects in coping with the instructional situation forecast in practice. Hence to this end, the study objectives are set up and launched as follows: 1) It provides the materials capable of endorsing view points for the primary school teachers who play a pivotal role on modernizing the mathematical education. 2) It works out the instructional materials bearing relation on logical terms and their definitions 3) It purveys the rudimentary materials for ameliorating the mathematical curriculum. However, put it to the point, taken for granted that logical instruction covers a wide range of contents and methods, this study can't but give lots of limit only to simple principles forming the foundations of logical terms, definitions, and axiomatic methods. Moreover, in the primary school mathematical learning sign logic or logical verification is not in fact directed enough to be suitable for children, but logical learning is undertaken for clarifying mathematical thinking, so with mind on this stand, we allege we addressed ourselves to extract and frame the material concerning logical terms. In chapter Ⅱ the logical terms, logical corallory, logical definition, and axiomatic methods, which this study purports to delve into, are given second thought in light of logical facets. In chaptor Ⅲ we consolidated the teaching stantpoint analyzing the primary school mathematical textbooks(1st grade to 6th grade) and seeking the learning situation given the leeway for bringing logical terms into classroom. In chapter Ⅳ and Ⅴ the learning materials and logical terms, which underlie the learning of logical definition and axiomatic methods, are boiled down and worked out, and simultaneously referenciel materials, serving the intent of the teachers' further prosecution of study thereon, are presented as well. Alongside, pulling ahead with the above work, we will state a few views in point gleaned from this study. The logical learning for orienting logic righteously should deserve all the more emphatic care and systemic inculcation in today's mathematical teaching targeted for modernization. With a view to further doing that now the teachers should take an advanced pace ever farther than they took a luckewarm pose about mathematical education, and should have a close insight into logic to the effect that they can make exact treatment and judgment of them. Foremost of all, they should conduct still more efficient teaching by classifying and arranging logical terms founded on sagacious understanding in children's learning or by guiding them in the direction that they can have a thorough grip of relationships to concepts. If carried out, in particular not less notice should be given to the following issues: 1) Accurate understanding as for the logical terms(be, not be, and, or, all, any, at least, at most, no less than, if-then) or signs(→,⇒,⇔,? etc.) are the cornerstone of logical instruction. 2) Considered that axiomatic methods are a nucleus of modern mathematics, propelling thinking abilitiy underpinned by sound ground is not only a momentum of childlike deductive thinking, but an axis of logical verification to be advancd into a better dimension in the forth coming days. In the fear of knowing what tomorrow will bring, the teachers should deliberate to the full what is to be determined as axiom and what logical learning is to be performed. 3) Keeping in mind that mathematic text books are organized so as to aggrandize laws and concepts into larger and more complex ones by degrees in view of child developmental stages, teachers should teach them to make clearer the definitions of objects. 4) In the current mathematical learning legic bears germane relationships on "set concept", hence logical learning should be progressed on the basis of sets. 5) Teachers should take persistent account of the fact that there still exists the case that analogous, inductive, or deductive thinking is acted upon otherwise than intuitive thinking either in theoretic development or in the disposal of problems. To be exact, the following problems are put forward as the supreme tasks of the future logical instruction: 1) To what extent is the purview of logical teaching fixed and how is the pertinent instructional framework organized in the scope of teaching? 2) The signs(→,⇒,⇔, ? etc.) of logic are included in the mathematical texts, besides, to what degree and in what way are new signs introduced in any grade from now on? 3) In what way is it the most praiseworthy for the concepts of sets to be structured so as to make inalienable ties with logic? 4) In teacher's in-service training what are the concepts concerning logic and the problems of training hour allotment. to be contemplated? In addition to these matters discussed above, the field-study which invokes interest in the front teacher's logical teaching had better be recommended and encouraged even more positively than the past. To sum up, it goes without saying that this study has brought about most limited materials in search of teaching methods making the groundwork for logical terms, definitions and axiomatic methods. Out of this result as such it is very difficult to hazard any rash conclusion on logical teaching with far-flung characteristics. However, we wish the study of this area would gain far open ground sufficiently enough to brush up the teaching methods of the field teacher's and remain meaningful materials later on Conducive to ironing out any thorny problems stemming from furtherance of research meeting our expectation in the foreseeable future and render a major boost to more intensive study, now that to date any convincible studies of this area have not yet come fresh in many years.

ESR 측정시 영향을 주는 인자들에 관한 연구

김인환 제주한라대학 2001 論文集 Vol.25 No.-

Erythrocyte Sedimentation Rate(ESR) measures the suspension stability of the erythrocytes. When Whole blood is mixed with anticoagulant and placed in a perpendicular tube,the red blood cells sink because they are heavier than the plasma in which they are suspended. Results are expressed in millimeters per hour,ESR is a simple,inexpensive laboratory test as a sickness Conventional methods have disadvantges of difficulty in standadiztion and quality Factors which affects ESR are temperarure, angle of ESR tube,vibration, time.and so on Then the purpose of this study was to find out the best way of measures by ESR The results of the study are summarized as follows: 1. ESR mean value is 15.9㎜/hr in 37℃, 10.5㎜/hr in room temperature, 4.5㎜/hr in 4℃. 2. ESR mean value 10.5㎜/hr in 90˚ 20.4㎜/hr in 30˚ 3. ESR mean value 7.3㎜/hr in 30min, 10.5㎜/hr in 60min, 18.7㎜/hr in 90min, 29.3㎜/hr in 120min. 4. ESR mena value 17.5 ㎜/hr in Vibration, 10.5㎜/hr in No Vibrtion.

응집공정에 적합한 In-Line 정적혼화기를 이용한 혼화공정의 개선

정철우,강민수,최시환,정수일,손인식,강임석 대한상하수도학회 2003 상하수도학회지 Vol.17 No.3

The rapid mixing process for coagulation is a critical component in a water treatment plant. However, at the present time a detailed understanding of the rapid mixing by in-line mixer or generally accepted criteria for the design of in-line static mixer are not available. The aim of this work is therefore to improve the understanding of how the in-line static mixer works and how to better utilize it in coagulation process in water treatment. To investigate the performance of static mixer, coagulation experiments were conducted to compare the static mixer to the traditional backmixer under several coagulation conditions. Experiments were also performed to compare the coagulation efficiency of different mixing type of static mixer which were made using different flow rates and the number of elements equipped in a pipe. The static mixer performed better than the backmixer for all coagulation and mixing conditions tested. Especially, the static mixer was very effective in the surface charge neutralization, as showing higher reduction of negative charge with increasing mixing intensity. However, little difference was observed in the performance of the static mixer equipped with 2, 3, and 5 elements. Also, in a series of bench-scale studies of rapid mixing, the in-line static mixer performed better than the traditional backmixer for both adsorption and charge neutralization (A/N) mechanism and sweep coagulation mechanisms. Especially, the static mixer was more efficient at producing A/N mechanism conditions as a result of its fast and uniform dispersion of the coagulant.

순천대학교 농과대학 개편 방안

임행진,배인휴,임준택,배영환 순천대학교 1996 大學發展硏究論文集 Vol.2 No.-

1. 대학 명칭 변경 농과대학을 생명자원 과학대학으로 개편 2. 학부제 운영 방안 1) 제1차안에 따른 6개 학부로 개편하되 추가적인 여론 수렴이 반드시 요망됨. 2) 학부 운영시 정원 감축 요망 현행 395명 → 300명 (24% 감축) 3) 학부 구성시 전공의 세분화는 지양하되 통합을 위한 새로운 분야는 인정한다. 3. 교과과정의 운영 1) 교양과목―외국어 및 전산 교육 강화 2) 전공과목 ① 강의 책임시수를 하향 조정하여 강의 내실화 도모 ② 유사과목 중복 개설 지양 ③ 복수전공제 도입 ④ Team teacing, 동일 과목 분반제 등의 도입으로 전문성 제고 3) 교과과정의 개편 절차 (1) 농대에 교과과정 개편위원회를 설치하여 자체 의견을 수렴 (2) 교과과정 개편위원회에서 ① 교양과목 이수 학점 조정 ② 학부(전공)간 중복 및 유사 교과목 조정 ③ 공통 과목 담당 교수진과 강의분담 방법 결정 ④ 복수전공 허용 범위 및 시행 방안 조정 4. 대학 발전 방안 1) 농과대학 특성화 시설원예 분야로의 특성화유도 2) 대 농민 기술지원 센타 설립을통한 현장애오 해결 연구부, 교육부, 지도부, 농업정보부, 식물병원 등 설치 3) 대학의 자립 능력 배양 ① 농대 발전기금 조성, 농대 부석기관의 자체 수익사업 운영 ② 부속기관의 수익을 재투자할 수 있도록 제도 개선 4) 연구 여건 개선 ① 연구 전담 교수제 확대 시행 ② 공동기기동 설치 및 전공별 공동기기실 운영 The problems that College of Agriculture in Korea are confronted with consist of a few number of faculty members in very department, and hence too many lecture hours per prefessor, departments with similar speciality, duplicated subjects, and hence duplicated lectures in similar subjects, poor experimental equipments, poor extension system, and a small amount of budget. It would be necessary to reorganize the system of College of Agriculture to solve these problems. The objective of the study is to construct the direction of reorganization of College of Agriculture in Sunchon National University. For the objective, survey composed of all professors in the Agricultural College and discussions among committee members were adopted. Survey data was collected and analysed. Through the study, reorganization strategies were built as the point of change of college name, administration of school system by unifying departments with similar major area, basic directions in reconstructing the curriculum for the school system, and strategies for the growth of the College. 1) Name of College of Agriculture will be changed to College of Life and Resource Science. 2) College of Agriculture can be reorganized into six schools based on survey, and for more concrete reorganization, additional opinions must be gathered. Number of incoming student can be reduced for school system from 395 at present to 300 (24% reduction). Finely specialized major should be prohibited, but addition of departments or speciality of new research area can be allowed for the establishment of administration of school system. 3) In management of curriculum, foreign language and computer science should be reinforced as general course in the school system. Obligated lecture hours of professor should be reduced, which would enhance the quality of lecture, and offerring lectures with similar subjects should be restricted. Dual major system is going to be allowed. Team teaching and class separation for the same subject should be allowed for the enhancement of lecture quality. In curriculum revision process, committee of curriculum revision in College of Agriculture must be set up and gather opinios for better revision. The committee regulate the credits for the general course, control overlapping or similar subjects among the schools(majors), select lectures for team teaching and the way of class separation in the same subject. They also provide permitted limits of and the way of conducting dual major system. 4) For further growth of the college, the following items should be satisfied. With the limited number of faculties, concentrating facilities and research capability of the college into specialized area is needed to enhance the competitive power of the college. In this study, the committee agreed to select horticultural area in greenhouse as the specialized area. This will be achieved gradually by employing new faculty members with major in this area and conducting cooperative research among faculty members. An extension system to train farmers for the newly developed technologies in agriculture should be established. In this facility, farmers can exchange their experiences among them, and farmers and the university faculty members can conduct experiments to solve problems occurred in farming practices. The extension system consists of division of reasearch, education, advise, information in agricultural area, and diagnosis of pest and diseases. Annual budget of the college largely depends upon the budget from the Ministry of Education. With the limited budget, it is almost impossible for the college to invest into the area where college faculty members intend to for the farmers. Collection of a fund for the growth of the college is needed. This fund can be gathered either from the alumni, faculty members and students or by reinvesting the profit from experimental farm of the college. The system for the reinvestment of the profit from appendges of the college should be established. The condition of research should be improved. This can be achieved by employing full-time researchers as faculty members and reducing lecture load of professors. Building for the center of cooperative research and systematic installation of experimental facility and equipments might also be needed for the improvement.

Synergistic effect of melamine in combination with cyanuric acid on urinary tract toxicity in rats

Jong-Choon Kim, In-Chul Lee, Sung-Hwan Kim, Hyung-Sun Baek, Sung-Soo Kang 충북대학교 동물의학연구소 2013 Journal of Biomedical and Translational Research Vol.14 No.3

The present study investigated the urinary tract toxicity of melamine alone or in combination with cyanuric acid in rats. Male rats were orally administered melamine alone (800 mg/kg) or melamine plus cyanuric acid (50 mg/kg each) for 3 consecutive days. Although melamine treatment did not show any significant difference in body weight, kidney or urinary bladder weight, serum blood urea nitrogen (BUN) or creatinine levels, it caused a decrease in urinary pH and mild histopathological alterations in the kidney and urinary bladder. In contrast, co-administration of melamine and cyanuric acid induced a decrease in body weight, an increase in kidneys and urinary bladder weights, and an elevation in serum BUN and creatinine levels, which were not observed in animals treated with melamine alone. Histopathological examination showed that the incidence and severity of histopathological lesions in the kidney and urinary bladder were much higher than those in the melamine group. Urinalysis revealed an increase in urine occult blood, leukocytes and protein and a decrease in urinary pH. These results indicate that concomitant administration of cyanuric acid synergistically potentiated the urinary tract toxicity induced by melamine in rats. In this study, we first demonstrated the synergistic toxic effects of melamine in combination with cyanuric acid on urinary bladder and urinalysis in rats.

ERK1/2-Mediated Schwann Cell Proliferation in the Regenerating Sciatic Nerve by Treadmill Training

Seo, Tae Beom,Oh, Myung-Jin,You, Byoung-Gun,Kwon, Ku-Birm,Chang, In-Ae,Yoon, Jin-Hwan,Lee, Chan-Yong,Namgung, Uk Mary Ann Liebert 2009 JOURNAL OF NEUROTRAUMA - Vol.26 No.10

<P>Proliferation of Schwann cells in the injured peripheral nerve supports axonal regeneration, and physical training in experimental animals has been shown to promote nerve regeneration. Extracellular signal-regulated kinase 1/2 (ERK1/2) activity can mediate neuronal responses to lesion signals, but its role in non-neuronal cells in the injured area is largely unknown. Here we report that treadmill training (TMT) facilitates axonal regeneration via the upregulation of phospho-ERK1/2 protein levels in Schwann cells in the injured sciatic nerve. Low-intensity, but not high-intensity, TMT increased neurite outgrowth of dorsal root ganglion (DRG) sensory neurons and potentiated Schwann cell proliferation. TMT elevated levels of GAP-43 mRNA and protein, and phospho-ERK1/2 protein in the injured sciatic nerves. TMT also enhanced phospho-c-Jun protein levels in the injured nerve. In-vivo administration of the ERK1/2 inhibitor PD98059 eliminated phospho-c-Jun, suggesting ERK1/2 phosphorylation of the c-Jun protein. PD98059 treatment decreased levels of BrdU-labeled proliferating Schwann cells in the distal portion of the injured nerve, and delayed the axonal regrowth that was promoted by TMT. The present data suggest that increased ERK1/2 activity in Schwann cells may play an important role in TMT-mediated enhancement of axonal regeneration in the injured peripheral nerve.</P>