• Title/Summary/Keyword: 반복투여

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Response of dairy cows to glucose administration (유우(乳牛)에 있어서 포도당(葡萄糖) 투여(投與)의 반응(反應)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Sakai, Takeo;Yoon, Chong-sam;Satoh, Tsuneo;Lee, Won-chang
    • Korean Journal of Veterinary Research
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    • v.33 no.1
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    • pp.145-149
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    • 1993
  • 실험대상(實驗對象)으로서 유우(乳牛) 5두(頭)에게 50% 포도당(葡萄糖) $500m{\ell}$를 생리적식염수(生理的食鹽水)에 혼합(混合) 13~15회(回) 반복(反復) 경정맥(jugular vein)을 통해 주입후(注入後) 혈중(血中) insulin수준(水準)과 Langerhans islets의 조직화학(組織化學)을 관찰(觀察)한바, 혈중(血中) insulin의 수준(水準)은 포도당(葡萄糖)의 투여전(投與前)에 비(比)하여 4~11배(倍)나 증가(增加)됨이 관찰(觀察)되었다. 한편, Langerhans islet의 B cell도 포도당(葡萄糖)의 투여회수(投與回數)에 따라 특이(特異)하게 주름이 관찰(觀察)되었는데 이는 B cell에서의 insulin 합성능(合成能)을 높이는데 그 원인(原因)이 있었다고 본다.

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Evaluation for dispersive refractive indices in IR regions of amorphous and crystalline $Ge_2Sb_2Te_5$ thin films (비정질 $Ge_2Sb_2Te_5$ 박막의 IR 영역에서의 복소굴절률 평가)

  • Kim, Jin-Hee;Lee, Hyun-Yong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.334-345
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    • 2008
  • 컴퓨터의 발달과 더불어 현대사회는 기록하고 보존해야할 정보의 양이 점점 방대해 지고 있다. 그로 인해 자기기록매체처럼 정보를 사용자의 편의에 따라 반복적으로 기록하고 재생할 수 있는 광기록매체에 대한 관심이 증가되고 있다. $Ge_2Sb_2Te_5$(GST)는 기존의 CD-RW나 Floppy Disk(FD)를 대체할 차세대 기록매체로 주목받고 있다. 따라서 본 연구에서는 비정질상과 결정상으로 변하는 성질을 가지고 있는 GST롤 상변화 기록매체로서 이용하기 위해 굴절률을 평가하였다. 시료는 5N의 순도를 갖는 Ge, Sb, Te 물질을 준비하고 조성비에 맞추어서 석영관에 진공 봉입한 후 용융-냉각법으로 벌크를 제작하였고 열증착 방법으로 Si 및 유리 기판위에 1000nm 두께로 박막을 제작하였다. UV-Vis-IR spectrophotometer를 사용하여 반사도와 투과도를 측정하였고 측정한 스펙트럼을 이용하여 Swanepoel method로 굴절률을 계산하였다. 본 연구진이 자체 개발한 계산툴에 실험값을 대입하였고 실험에 의해 얻은 투과도와 계산툴에 의해 얻은 투과도 스펙트럼을 비교하였다.

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Single and Four-Week Intravenous Toxicity Studies of a Novel Cephalosporin Antibiotic Agent, IDC-7181, in Rats (새로운 Cephalosporin계 항생제 IDC-7181의 랫드에 대한 단회 및 4주 반복 정맥투여 독성시험)

  • 장호송;황재식;신장우;정은용;신지순;이수해;이종성;강재훈;김기원
    • Toxicological Research
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    • v.18 no.2
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    • pp.195-203
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    • 2002
  • This study was performed to evaluate single and repeated-dose toxicities oj a new cophalosporin antibiotic agent IDC-7l81 in Sprague-Dawley rats. IDC-7181 was injected intravenously to rats at dose levels of 0, 3.2, 16, 80, 400 and 2,000 mg/kg/day for single-dose toxicity study and at dose levels of 0, 10, 50 and 250 mg/kg/day for 4-week repeated-dose toxicity study. In both studies, there were no dose-related changes in mortality clinical signs, body weight changes, food and water consumption, opthalmoscopy, organ weights, urine analysis, biochemical examination, and hematological findings of all animals treated with IDC-7l8l. Gross and histopathological findings revealed no evidence of specific toxicity related to IDC-7181. These results suggest that the intravenous maximum tolerated dose value of IDC-7181 may be over 250 mg/kg and $LD_{50}$ value may be over 2,000 mg/kg in rats.

Single and Four-Week Subcutaneous Toxicity Studies of a Bee Venom Extracts (F1, F3) In Rats (봉독 추출물(Fl, F3)의 랫드에 대한 단회 및 4주 반복 피하 투여 독성시험)

  • 박기수;조성대;안남식;정지원;양세란;박준석;홍인선;서민수;조은혜
    • Toxicological Research
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    • v.19 no.1
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    • pp.51-66
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    • 2003
  • This study was performed to evaluate single and repeated-dose toxicities of Bee Venom Extracts (F1, F3) in Spraque-Dawley. F1 was injected subcutaneously to rat at dose levels of 0, 0.0002, 0.002, 0.02 mg/kg/day for single-dose toxicity study and repeated-dose toxicity study. F3 was injected subcutaneously to rat at dose level of 0, 0.003, 0.03, 0.3 mg/kg/day for single-dose toxicity study and repeated-dose toxicity study. In both studies, there were no dose related changes in mortality, clinical sign, body weight change, food and water consumption, opthalmoscopy, organ weights, urine analysis, biochemical examination, and hematological findings of all animals treated with Bee Venom (F1, F3). Gross and histopathological findings revealed no evidence of specific toxicity related to Bee Venom (F1, F3). These results suggest that the subcutaneous NOEL (No Observed Effect Level) of Bee Venom (F1, F3) may be over F1 -0.02 mg/kg, F3-0.3 mg/kg.

Effect of repeated Paecilomyces japonica treatment on rats (Paecilomyces japonica의 반복투여가 랫드에 미치는 영향)

  • Kim, Yong-Bum;Hong, Da-Hae;Cho, Eun-Sang;Im, Wanjung;Kim, Il-Hwan;Son, Hwa-Young
    • Korean Journal of Veterinary Research
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    • v.54 no.1
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    • pp.31-38
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    • 2014
  • Cordyceps is a fungus used as a traditional medicine in China, Japan, and Korea. Paecilomyces (P.) japonica is a new cordyceps that was recently cultivated on silkworm pupae in Korea. The present study evaluated the toxicological effects of P. japonica in rats. Forty rats were treated with oral doses of P. japonica (0, 20, 100, or 500 mg/kg/day) for 4 weeks. Twenty additional rats were treated with 0 or 500 mg/kg/day of P. japonica for 4 weeks and then maintained for 2 weeks without treatment. Clinical signs, body weight, food and water consumption, and organ weight as well as hematology, serum biochemistry, and histopathology data were examined. Body weight gain of the group treated with 500 mg/kg/day was significantly reduced. Microscopically, karyomegaly, single cell necrosis, and mitosis were observed in the renal tubular epithelium of all treated groups. In conclusion, P. japonica caused a reduction of body weight and renal injury in rats. The no observed adverse effect level (NOAEL) of P. japonica was less than 20 mg/kg/day.

A 28 Day Repeated Dose-Oral Toxicity Studies of Arisaema Rhizome Aqueous Extracts in Sprague-Dawley Rats (천남성 추출물의 Sprague-Dawley 랫드를 이용한 28일 반복 경구투여 DRF독성시험)

  • Kim, Min-Kyeoung;Lee, Ji Sun;Park, Yeong Chul;Choi, Sun Mi;Lee, Sanghun
    • Korean Journal of Plant Resources
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    • v.28 no.4
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    • pp.371-381
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    • 2015
  • The object of this study was to obtain single oral dose toxicity of Arisaema Rhizome (Arisaema amurense f. serratum (Nakai) Kitag) aqueous extracts. Arisaema Rhizome (Chunnamsong in Korean) is one of the most important folk remedy plants used in Asia. In the study, a 28-day rat oral gavage study has been conducted with the extracts from Arisaema Rhizome at dose of 1,250, 2,500 and 5,000 ㎎/㎏/day. The following endpoints were evaluated: clinical observations, body weight, gross and microscopic pathology, clinical chemistry, and hematology. Based on the analysis of these endpoints, it was estimated that NOEL (no observed effect level) for male rats and NOAEL (no observed adverse effect level) for female rats are 5000 ㎎/㎏/day of the water-extracts from Arisaema Rhizome.

Repeated Dose 90-Day Oral Toxicity Study of Modified Samjung-Hwan in Sprague-Dawley Rats (삼정환의 랫드를 이용한 90일 반복 경구투여 독성시험)

  • Kim, Min-Jee;Lee, Myeong-Jong;Kim, Hojun
    • Journal of Korean Medicine for Obesity Research
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    • v.18 no.1
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    • pp.36-49
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    • 2018
  • Objectives: The study is aimed at evaluating the possible toxicity in 90-day repeated oral administration of modified Samjung-hwan (mSJH) in Sprague-Dawley (SD) rats. This study was conducted to detect the no-observed adverse effect level (NOAEL). Methods: Modified SJH extract was administered orally in male and female SD rats at dose of 0, 1,000, 2,000, 4,000 mg/kg. Each group consisted of 10 rats of each gender. The modified SJH extract was given once a day for 90 days. We monitored the changes of mortalities, clinical signs, body weight changes, food consumption, ophthalmologic findings, urine analysis, hematology, serum biochemistry, necropsy findings, organ weights, histological markers of all animals treated with modified SJH extract during the study period. Results: There were no toxicologically significant changes in mortalities, clinical signs, body weight gains, food consumption, ophthalmologic findings, urine analysis, hematology, serum biochemistry, necropsy findings, organ weights, histological markers in any of rats tested. Conclusions: The NOAEL of the modified SJH extract in male rats and no observed effect level (NOEL) in female rats are considered 4,000 mg/kg.

Plasma Sex Steroid Hormone Profiles in Artificially Maturing Wild Eel, Anguilla japonica (자연산 뱀장어의 인위적인 성숙 유도에 따른 혈중 성호르몬 변동)

  • Kim, Dae-Jung;Kim, Eung-Oh;Park, Min-Woo;Cho, Yong-Chul;Lim, Sang-Gu
    • Journal of Aquaculture
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    • v.19 no.4
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    • pp.267-274
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    • 2006
  • To understand the changes in plasma levels of sex steroids in the wild Japanese eel Anguilla japonica during artificially maturing process, eels received weekly intraperitoneal injections of a water-in-oil (W/O) type emulsion with Freund`s incomplete adjuvant containing salmon pituitary extract (SPE; 20 mg pituitary powder/fish) were examined. In the weekly Eel's Ringer-treated control wild eels, the body weight (BW) changes of fish decreased slowly during the experiment period. Plasma testosterone (T), $estradiol-17{\beta}\;(E_2)$ and $17a,20{\beta}-dihydroxyprogesterone$ (DHP) levels did not change significantly at the end of the experiment. In the weekly SPE-treated silver eels, however, rapid increase in BW changes occurred after 6 to 10 weeks, and the oocytes of all fish were observed to be in the migratory nucleus stage. Furthermore, significant increase in sex steroid hormones (T and $E_2$) levels occurred from 6 weeks. In the weekly SPE-treated yellow eels, the BW changes of fish increased slowly at 6 weeks and then increased. In these fish, the oocytes were at the tertiary yolk globule stage even at the end of the experiment. Plasma sex steroid hormones profiles revealed individual variability in SPE-treated yellow eels. Plasma T and $E_2$ levels significantly increased at 8 weeks and after 6 weeks, respectively, in SPE-treated yellow eels. In the weekly SPE-treated wild eels (silver and yellow eels), however, plasma DHP levels did not change significantly during the experiment period. In silver eel, final maturation could be induced by weekly administration of SPE using W/O type emulsion.

Cardioprotective Effect by Preconditioning with Calcium-free Solution (칼슘결핍용액 투여 전처치에 의한 심근보호 효과)

  • 조대윤;이종화;김호덕
    • Journal of Chest Surgery
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    • v.32 no.9
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    • pp.773-780
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    • 1999
  • Background: It has been demonstrated that brief periods of calcium depletion and repletion (calcium-free preconditioning, CP) have cardioprotective effects as seen in ischemic preconditioning(IP) which enhances the recovery of post-ischemic contractile dysfunction and reduces the incidence of reperfusion-induced arrhythmia or infarct size after a prolonged ischemia. In the present study, we tested this paradoxical phenomenon in isolated rabbit hearts. Material and Method: Hearts isolated from New Zealand white rabbits(1.5∼2.0 Kg body weight) were perfused with Tyrode solution using the Langendorff technique. After stabilizing the baseline hemodynamics, the hearts were subjected to 45 minutes of global ischemia followed by 120 minutes of reperfusion with IP(IP group, n=7) or without IP (ischemic control group, n=7). IP was induced by a single episode of 5 minutes global ischemia and 10 minutes reperfusion. In the CP group(n=7), the hearts were subjected to perfusion with Tyrode solution with calcium depletion for 5 minutes and repletion for 10 minutes, and 45 minutes of ischemia and 120 minutes of reperfusion. Left ventricular function including developed pressure, dP/dt, heart rate, left ventricular end-diastolic pressure and coronary flow was measured. Infarct size was determined by staining with 1% triphenyltetrazolium chloride and planimetry. Data were analyzed by a one-way analysis of variance and Tukey's post-hoc test. Result: In comparison with the ischemic control group, IP significantly enhanced the recovery of the left ventricular function including the left ventricular developed pressure, contractility, and coronary flow; in contrast, these functional parameters of the CP group tended to be lower than those of the ischemic control group. However, the infarct size was significantly reduced by IP or CP(p<0.05). Conclusion: These results suggest that in isolated Langendorff-perfused rabbit heart model, CP(induced by single episode of 5 minutes calcium depletion and 10 minutes repletion) could not improve the post-ischemic contractile dysfunction(after a 45-minute global ischemia) but it has an infarct size-limiting effect.

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Interpretation of the Manufacturing Characteristics and the Mineral and Chemical Composition of Neolithic Pottery Excavated from the Jungsandong Site, Yeongjong Island, South Korea (영종도 중산동 신석기시대 토기의 광물 및 화학조성과 제작특성 해석)

  • Lee, Chan Hee;Kim, Ran Hee;Shin, Sook Chung
    • Korean Journal of Heritage: History & Science
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    • v.51 no.1
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    • pp.4-31
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    • 2018
  • The Neolithic pottery excavated from the Jungsandong site has been classified into four types of pottery (I: feldspar type, II: mica type, III: talc type and IV: asbestos type) according to their mineral composition. These four types of potteries generally appear to have undergone incomplete firing, while the level of oxidation in the type I pottery objects, which have a relatively higher clay content, was found to be particularly low. The type III objects, which have a high talc content, are judged to have been somewhat slow in removing carbon because they contain saponite belonging to the smectite group. Of the four types of pottery, type IV showed the highest redness and the most uniform characteristics, thus indicating a good level of oxidation. In particular, fixed carbide (C; 33.7 wt.%) with a thickness of about 1mm, and originating from organic substances, was detected inside the walls of the type I pottery, while the deep radial cracks in the outer surfaces of the pottery are thought to have been caused by repeated thermal shocks. Given that all of the pottery except for the type I artifacts are considered to be have been made for storage purposes, those containing talc and tremolite are easy to done liquid storing vessels based on an analysis of their material characteristics. As for the type II relics, which are composed of various minerals and exhibit poor physical properties, they seem to have been used for simple storage purposes. As domestic talc and asbestos mines were concentrated in the areas of Gyeonggi, Gangwon, Chungbuk, and Chungnam, it seems likely that talc and tremolite were produced as contiguous minerals. Considering the distance between the remains in Jungsandong and these mines and their geographical distribution, there is a possibility - albeit somewhat slight - that these mines were developed for the mining of various minerals. Although ultramafic rock masses - such as serpentine capable of generating talc and tremolite - have not been found in the Jungsandong area, limestone and biotite granite containing mica schist have been identified in the northwestern part of Yeongjong Island, indicating that small rock masses might have formed there in the past. Therefore, it is judged necessary to accumulate data on pottery containing talc and tremolite, other than the remains in Jungsandong, and to investigate the rocks and soils in the surrounding area with greater precision. The firing temperatures of the pottery found at the Jungsandong site were interpreted by analyzing the stability ranges of the mineral composition of each type. As a result, they have been estimated to range from 550 to $800^{\circ}C$ for the type I artifacts, and from 550 to $700^{\circ}C$ for the type I, II and IV artifacts. However, these temperatures are not the only factors to have affected their physical properties and firing temperature, and the types, particle sizes, and firing time of the clay should all be taken into consideration.