• 제목/요약/키워드: lethal range

검색결과 85건 처리시간 0.028초

저관리·경량형 옥상녹화를 위한 세덤류의 내서성 평가 (Hot Tolerance Assessment of Sedum spp. for Extensive Green Roof System)

  • 조홍하;손희준;강태호
    • 한국조경학회지
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    • 제40권6호
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    • pp.180-189
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    • 2012
  • 이 연구는 저관리 경량형 옥상녹화시스템을 위한 내서성 식물 선발을 목적으로 6종 세덤식물을 대상으로 처리 시간과 온도에 따라 전해질 용출, 엽록소 함량 변화 및 재생 실험을 실시하였으며, 토양수분과 고온스트레스와의 관계를 연구하였다. Logistic비선형 회귀분석을 이용하여 6시간의 고온 처리 후 5%의 토양 함수량의 치사 온도는 $45.1{\sim}48.0^{\circ}C$, 토양 함수량 10%, 15%의 경우 각각 $47.5{\sim}49.3^{\circ}C$, $48.6{\sim}52.8^{\circ}C$의 범위로 측정되었다. 고온스트레스는 처리 시 토양 수분이 높을수록 세덤류의 내서성이 높아졌다. 엽록소 함량은 처리 온도가 높을수록 함량이 낮아졌고, 토양 수분 함량이 낮을수록 분해 속도가 높아졌다. 토양 함수량 5% 시 고온에 대한 저항성은 S. reflexum>S. takevimense>S. middendorffianum>S. album>S. sieboldii>S. spurium의 순으로 나타났으며, 토양 함수량이 15%의 경우는S. album>S. reflexum>S. spurium>S. takevimense>S. middendorffianum>S. sieboldii의 순으로 나타났다. 토양의 수분 함량이 높을수록 S. album, S. reflexum, S. spurium의 내서성이 높아졌다. 이러한 결과는 재생 검사의 결과와 전해질 용출 평가에 일관성이 있는 것으로 증명되었다.

Ginsenoside Rh2 attenuates microglial activation against toxoplasmic encephalitis via TLR4/NF-κB signaling pathway

  • Xu, Xiang;Jin, Lan;Jiang, Tong;Lu, Ying;Aosai, Fumie;Piao, Hu-Nan;Xu, Guang-Hua;Jin, Cheng-Hua;Jin, Xue-Jun;Ma, Juan;Piao, Lian-Xun
    • Journal of Ginseng Research
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    • 제44권5호
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    • pp.704-716
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    • 2020
  • Background: Ginsenoside Rh2 (GRh2) is a characterized component in red ginseng widely used in Korea and China. GRh2 exhibits a wide range of pharmacological activities, such as anti-inflammatory, antioxidant, and anticancer properties. However, its effects on Toxoplasma gondii (T. gondii) infection have not been clarified yet. Methods: The effect of GRh2 against T. gondii was assessed under in vitro and in vivo experiments. The BV2 cells were infected with tachyzoites of T. gondii RH strain, and the effects of GRh2 were evaluated by MTT assay, morphological observations, immunofluorescence staining, a trypan blue exclusion assay, reverse transcription PCR, and Western blot analyses. The in vivo experiment was conducted with BALB/c mice inoculated with lethal amounts of tachyzoites with or without GRh2 treatment. Results and conclusion: The GRh2 treatment significantly inhibited the proliferation of T. gondii under in vitro and in vivo studies. Furthermore, GRh2 blocked the activation of microglia and specifically decreased the release of inflammatory mediators in response to T. gondii infection through TLR4/NF-κB signaling pathway. In mice, GRh2 conferred modest protection from a lethal dose of T. gondii. After the treatment, the proliferation of tachyzoites in the peritoneal cavity of infected mice markedly decreased. Moreover, GRh2 also significantly decreased the T. gondii burden in mouse brain tissues. These findings indicate that GRh2 exhibits an antieT. gondii effect and inhibits the microglial activation through TLR4/NF-κB signaling pathway, providing the basic pharmacological basis for the development of new drugs to treat toxoplasmic encephalitis.

Dithiopyr에 노출이 zebrafish의 유영 행동에 미치는 영향 (Exposure to Dithiopyr Alters Swimming Performance Parameters in Zebrafish)

  • 오준영;박은진;강성은;이승헌
    • 생명과학회지
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    • 제26권2호
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    • pp.181-189
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    • 2016
  • 본 연구에서는 발아전처리 제초제인 Dithiopyr (DTP)를 시험물질로 사용하여 급성 독성시험을 평가하고, zebrafish의 행동에 미치는 영향을 연구하였다. 급성 독성시험 결과 zebrafish에서의 DTP의 LC50값은 14.49 μM이었다. 또한 DTP 노출이 유영 패턴에 미치는 영향을 관찰하기 위하여 아치사농도(2.5-20 μM)에서 novel tank test (NTT)와 open field test (OFT)의 두 가지 행동실험을 실시하였다. NTT를 실시한 결과, 하층부의 머무는 시간 및 최초로 상층부에 들어간 시간, 회전각, 부동 시간의 경우 control 그룹과 비교하여 통계적으로 유의성 있게 농도 의존적으로 증가하였다(p<0.05). 또한 상층부에 진입한 횟수 및 평균 유영속도에서 통계적인 유의성 있는 감소현상이 확인되었다(p<0.05). OFT를 실시한 결과, 총 이동 거리 및 평균 유영속도에서 유의성이 있는 감소현상이 확인되었다(p<0.05). 부동 시간 및 회전각, 굴곡유영에서는 유의성 있는 증가 현상이 확인되었다(p<0.05). 또한 Whole-body cortisol level 측정 결과, 저농도 노출 그룹에서만 유의성 있는 증가가 관찰되었으나(p<0.05), 5와 10 μM에서는 유의성 있는 차이가 관찰되지 않아 농도의존적으로 감소하는 것을 확인하였다.

Second-Line Irinotecan after Cisplatin, Fluoropyrimidin and Docetaxel for Chemotherapy of Metastatic Gastric Cancer

  • Kucukzeybek, Yuksel;Dirican, Ahmet;Erten, Cigdem;Somali, Isil;Can, Alper;Demir, Lutfiye;Bayoglu, Ibrahim Vedat;Akyol, Murat;Medeni, Murat;Tarhan, Mustafa Oktay
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권6호
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    • pp.2771-2774
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    • 2012
  • Aim: Tumors of upper gastrointestinal tract are among the cancers that have a quite lethal course. Cytotoxic chemotherapy is the most efficient therapeutic modality for metastatic gastric cancer. In patients who do not respond to first-line treatment, the response rate to second-line therapies is generally low and the toxicity rates high. This study concerned the efficacy and the side effect profile of second-line therapy with irinotecan in the patients who were being followed-up with the diagnosis of metastatic gastric cancer in $\dot{I}$zmir, Turkey. Materials and Methods: We retrospectively evaluated the efficacy and toxicity in 31 patients with metastatic gastric adenocarcinoma who presented to the polyclinic of Medical Oncology of Izmir Ataturk Education and Research Hospital between May 2008 and July 2011. All received chemotherapy regimens containing cisplatin, fluoropyrimidine (5-FU) and docetaxel as the first-line therapy for late stage disease. Irinotecan as a single agent was given at a dose of 210 mg/$m^2$ on each 21 days. Irinotecan (180 mg/$m^2$ on day 1), 5-FU (500 mg/$m^2$ on days 1-2) and leucovorin (LV; 60 mg/$m^2$ on days 1-2) as a combined regimen were given over a 14 day period. Results: Median age was 54 (range, 31-70). Irinotecan was given as a combined regimen for median 6 cycles (range, 3-12) and as a single agent for median 3 cycles (range, 1-10). Metastases were detected in one site in six patients (19%), in two different sites in 17 patients (55%) and in three or more sites in eight patients (26%). Four patients (12.9%) showed partial response and six patients (19.3%) showed stable disease. Progression-free survival (PFS) was found to be 3.26 months (95% CI, 2.3-4.2). Median overall survival (OS) was found to be 8.76 months (95% CI, 4.5-12.9). The most commonly seen grade 3/4 side effect was neutropenia but the the therapy was generally well-tolerated. Conclusions: In this study, it was demonstrated that second-line therapy with irinotecan given following the first-line therapy with cisplatin, fluoropyrimidine (5-FU) and docetaxel was efficient and safe. Further studies are needed for confirmation.

Single Oral Dose Toxicity Study of an Alcohol Extract of Bombus ignitus pupae in Rats

  • Ahn, Mi-Young;Han, Jea-Woong;Yoon, Hyung-Ju;Hwang, Jae-Sam;Park, Hae-Chul;Seo, Yun-Jung;Chung, Wan-Tae
    • International Journal of Industrial Entomology and Biomaterials
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    • 제19권1호
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    • pp.175-180
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    • 2009
  • Recently, as the male silkworm pupae, bee pupae have the potential that strengths men's vitality on vascular endothelial nitric oxide in endothelial cells. Especially we prepared alcohol extract of pupae of bumblebee, native bee named Hobakbul, Bombus ignitus. The alcohol extract of pupae of B. ignitus was administered to rats at doses of 0, 0.04, 0.2, 1 or 2 g/kg as a single oral dose. There were no observed clinical signs or deaths related to treatment in all the groups tested. Therefore, the approximate lethal dose of the alcohol extract B. ignitus pupae was considered to be higher than 2 g/kg in rats. Mild decreases in body weight gain in male were observed dose-dependently within B. ignitus pupae alcohol extract treated groups in dose response manner over 2 weeks. Throughout the administration periods, no significant changes in diet consumption, ophthalmologic findings, clinical pathology (hematology, clinical chemistry and coagulation) or gross pathology were detected. Minor changes in male and female rats were found in hematological parameters for all or partial of B. ignitus pupae extract treated groups but all the changes observed were within the physiological range. From these results, it was concluded that there was no-evidence of specific toxicity related to the ingestion of alcohol extract of B. ignitus pupae.

Effects of Artificial UV-B and Solar Radiation on Four Species of Antarctic Rhodophytes

  • Han, Tae-Jun;Park, Seon-Joo;Lee, Min-Soo;Han, Young-Seok;Kang, Sung-Ho;Chung, Ho-Sung;Lee, Sang-Hoon
    • Ocean and Polar Research
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    • 제23권4호
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    • pp.389-394
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    • 2001
  • During austral summer 1998 we examined the impacts of artificial UV-B and solar radiation on chlorophyll a content and fresh weight of four species of Antarctic red algae namely, Georgiella confluens, Iridaea cordata, Pantoneura plocamioides and Porphyra endiviifolium. These subject species were taken in consideration of clear demarcations of their vertical distribution and classified as shallow water group (Iridaea and Porphyra) and deep water group (Georgiella and Pantoneura). When irradiated with artificial UV-B at the irradiance of $2.0Wm^{-2}$ the shallow water inhabitants were much more resistant than the algae from deep water the fresh weight of which was reduced by 40-50% relative to control apart from loss of pigmentation. Direct solar radiation was lethal to the deep water group with a sign of complete bleaching whereas the shallow water group did not show any change in the physiological parameters. We were unable to discriminate difference in the algal sensitivity between UV-filtered and UV-transparent treatments since samples tested were either all unaffected or dead. Spectrophotometric measurements of methanolic extracts revealed a strong absorption peak in the UV range in the shallow water group of algae, Iridaea and Porphyra, but not in the deep water counterparts. Species difference in sensitivity to artificial UV-B and solar radiation is discussed in relation to biochemical and morphological characteristics and the role of the radiation in the algal vertical distribution is suggested from ecological perspective.

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Induction of Conditioned Taste Aversion to Korean Pine Nuts (Pinus koraiensis) Treated with Lithium Chloride in Red Squirrels (Sciurus vulgaris)

  • Kim, Eui-Kyeong;Kim, Won-Myeong;Park, Yung-Chul;Yoo, Byung-Ho;Kim, Jong-Kuk
    • Journal of Ecology and Environment
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    • 제31권4호
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    • pp.341-344
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    • 2008
  • We investigated the responses of red squirrels to pine nuts (Pinus koraiensis) treated with Lithium Chloride (LiCl) and the potential of the chemical for inducing conditioned taste aversion (CTA) in red squirrels. In red squirrels, nut feeding declined dramatically during the first 4 days after feeding with LiCl-treated nuts. The ratio of LiCl-treated nuts eaten to total nuts eaten declined from the $1^{st}$ day in LC-1 and the $2^{nd}$ day in LC-2, along with a general reduction in quantity eaten. Thus, feeding with LiCl-treated nuts induced CTA from the 2nd day after feeding, and CTA remained constant until the $4^{th}$ day, but disappeared on the $5^{th}$ day. The squirrels ate an average of $757.0{\pm}106.1mg$ (n = 2, range $682.0\sim832.0$) of LiCl before dying on the $16^{th}$ day of the study. The lethal dose of LiCl was 2.32 mg LiCl/g body weight, and the average amount of LiCl needed to induce CTA was $23.0{\pm}4.24mg$ (20 mg in LC-1 and 26 mg in LC-2).

Intravenous Single and Two Week Repeated Dose Toxicity Studies of Rice Cells-derived Recombinant Human Granulocyte-Macrophage Colony Stimulating Factor on Rats

  • Ji, Jung-Eun;Lee, Jung-Min;Choi, Jong-Min;Choi, Young-Hwa;Kim, Seok-Kyun;Ahn, Kyong-Hoon;Lee, Dong-Hoon;Kim, Ha-Hyung;Han, Kyu-Boem;Kim, Dae-Kyong
    • Toxicological Research
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    • 제23권4호
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    • pp.383-389
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    • 2007
  • Recombinant human granulocyte-macrophage colony stimulating factor (hGM-CSF) regulates proliferation and differentiation of hematopoietic progenitor cells and modulates function of the mature hematopoietic cells. In the previous study, we reported that hGM-CSF could be produced in transgenic rice cell suspension culture, termed rhGM-CSF. In the present study we examined the single and repeated dose toxicity of rice cells-derived hGM-CSF in SD rats. During single dose toxicity study for 7 days, there were no any toxic effects at any dose of from 10 to $1000{\mu}g/kg$. The lethal dose ($LD_{50}$) was not found in this range. Moreover, repeated dose toxicity study of 14-days period and at the doses of 50 and $200{\mu}g/kg$ (i. v.) of rhGM-CSF did not show any changes in food and water intake. There were also no significant changes in both body and organ weights between the control and the test groups. The hematological and blood biochemical parameters were statistically not different in all the groups. These results suggest that rhGM-CSF has no toxicity in SD rats.

A Thirteen-week Oral Dose Subchronic Toxicity Study of Isaria sinclairii in Rats

  • Ahn, Mi-Young;Han, Jea-Woong;Jee, Sang-Deok;Hwang, Jae-Sam;Hwang, Seok-Jo;Hong, Yoo-Na;Kim, Sung-Nam
    • Toxicological Research
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    • 제23권4호
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    • pp.363-371
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    • 2007
  • Isaria sinelairii (IS) was orally administered at doses of 0, 0.04, 0.2, and 1 g/kg/day over a 13-week period. There were no observed clinical signs or deaths related to treatment in all the groups tested. Therefore, the approximate lethal oral dose of I. sinclairii was considered to be higher than 1 g/kg in rats. Throughout the administration periods, no significant changes in diet consumption, ophthalmologic findings, organ weight, clinical pathology (hematology, clinical chemistry, coagulation, and urinalysis) or gross pathology were detected. Minor changes were found in hematological parameters for the 0.04 g/kg/day and 0.2 g/kg/day IS treated groups (triglyceride reductions of $20.1{\sim}46.6%$ and platelet increases), but all changes were within physiological range. Microscopic examination failed to identify any treatment-related histopathologic changes in the organs of the IS-treated rats other than nuclear enlargement (cellular atypia) of the tubular regions in the medulla of the kidney in the high dose group. From these results, one can conclude that the no-observed effect level (NOAEL) of I. sinclairii is less than 0.04 g/kg/day in rats.

$F_o$-값 측정 시스템의 개발 (Development of $F_o-value$ Measuring System)

  • 조현덕;한봉호;김상봉;옥영건
    • 한국수산과학회지
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    • 제25권6호
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    • pp.520-528
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    • 1992
  • 식품의 가열살균공정의 최적화는 에너지 소비의 성력화를 위한 공정 자동화와 제품의 미생물학적 안전성 및 영양적, 기호적 품질을 감안하여 이루어져야 한다. 본 연구에서는 이미 개발한 마이크로컴퓨터를 이용한 자동화 시스템을 개선하여 미생물학적 안전성 확보를 위한 가열살균기준 설정에 필수적인 $F_o-값 측정 시스템을 개발하였다. $F_o-값은 가열살균 중인 명태 고기풀의 냉점에서의 온도변화에 따라 순간치사율(lethal rate)을 구하고 전체 공정에서의 치사율의 합(integrated lethality)을 $F_o-값으로 나타내었다. 또한 정확도는 냉점에서의 열침투곡선으로부터 계산된 열확산도의 정확도로써 검토하였다. $F_o-값은 다양한 온도에서의 미세한 조건의 변화에도 불구하고 정확한 측정이 가능하였다. 또한 다양한 조건에서 동시에 계산된 명태 고기풀의 열확산도는 문헌상에 보고된 추정식으로 구한 열확산도와 큰 차이를 보이지 않았으며, 그 차이는 $\pm12\%$이내였다.

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