• 제목/요약/키워드: Lethal time

검색결과 181건 처리시간 0.028초

해양생물에 대한 생체실험 II. 백합에 대한 수은, 구리 및 카드뮴의 독성 (BIOASSAYS ON MARINE ORGANISMS II. ACUTE TOXICITY TEST OF MERCURY, COPPER AND CADMIUM TO CLAM, MERETRIX LUSORIA)

  • 박주석;김학균
    • 한국수산과학회지
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    • 제12권2호
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    • pp.113-117
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    • 1979
  • 백합에 대한 수은, 구리 및 카드뮴의 독성정도를 구명하기 위하여 $1978.6.28\~7.15$간 정수식으로 실험을 실시하였다. 실험결과 수은 및 구리 용액에는 농도가 커질수록 점액을 분비하는 개체가 많아졌으나 카드뮴용액과 정상해수에 투입한 백합은 점액을 방출하지 않았다. 1mg/l 농도의 수조에서 15시간후에 분비한 점액은 수은에서는 $42.9\%$, 구리에서는 $14.3\%$ 나타냄으로서 수은이 구리보다 혐기도가 더 컸다. 농도와 사망률과의 관계에서 96시간후에 반치사농도(96hr-LC50)는 수은 0.67mg/l, 구리 7.04mg/l, 카드뮴 7.10mg/l, 로서 독성의 순위는 수은-구리-카드뮴이었다. 또한 각수조에서 $50\%$의 폐사를 일으키는데 소요한 시간(Lethal Tim 50)은 일반적으로 농도가 클수록 L. T.50값이 작아짐으로서 일정 농도에서는 노출시간이 반응을 유발시키는 자극이 되고 있으며 실제 중금속의 40mg/l에서 L.T.50값은 수은 55.8시간, 구리 104.8시간, 카드뮴 111.9시간으로서 동일농도에서는 수은-구리-카드뮴순으로 사망이 일어 났음을 밝혔다.

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저관리형 옥상녹화를 위한 상록 지피식물의 내한성 평가 (Cold Tolerance Assessment of Ever Ground-cover Plants for Extensive Green Roof System)

  • 조홍하;이홍;손희준;강태호
    • 한국조경학회지
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    • 제40권4호
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    • pp.127-134
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    • 2012
  • 이 연구는 저관리 경량형 옥상녹화시스템을 위한 내한성 식물 선발을 목적으로 6종 식물을 대상으로 저온 처리시간과 온도에 따라 전해질 용출 평가와 재생 검사를 연구하였다. Logistic 비선형 회귀분석을 이용하여 전해질 용출 평가를 통하여 치사 온도는 $-16.1{\sim}-24.4^{\circ}C$ 범위로 예측되었으며, 저온에 대한 저항성은 Sedum reflexum > S. spurium > Ophiopogon japonicus > S. album > S. takevimense > Dianthus chinensis의 순으로 나타났다. 2012년 2월 최저 온도인 $-13.4^{\circ}C$에 모든 식물의 전해질 용출은 50% 이하로 나타났으며, 겨울철 최적기온 $-13.5^{\circ}C$ 이상의 지역에서 식물들을 옥상에서 안정적으로 생육될 수 있을 것으로 예측되었다.

Herbal Remedies for Combating Irradiation: a Green Anti-irradiation Approach

  • Lachumy, Subramanion Jothy;Oon, Chern Ein;Deivanai, Subramanian;Saravanan, Dharmaraj;Vijayarathna, Soundararajan;Choong, Yee Siew;Yeng, Chen;Latha, Lachimanan Yoga;Sasidharan, Sreenivasan
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권10호
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    • pp.5553-5565
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    • 2013
  • Plants play important roles in human life not only as suppliers of oxygen but also as a fundamental resource to sustain the human race on this earthly plane. Plants also play a major role in our nutrition by converting energy from the sun during photosynthesis. In addition, plants have been used extensively in traditional medicine since time immemorial. Information in the biomedical literature has indicated that many natural herbs have been investigated for their efficacy against lethal irradiation. Pharmacological studies by various groups of investigators have shown that natural herbs possess significant radioprotective activity. In view of the immense medicinal importance of natural product based radioprotective agents, this review aims at compiling all currently available information on radioprotective agents from medicinal plants and herbs, especially the evaluation methods and mechanisms of action. In this review we particularly emphasize on ethnomedicinal uses, botany, phytochemistry, mechanisms of action and toxicology. We also describe modern techniques for evaluating herbal samples as radioprotective agents. The usage of herbal remedies for combating lethal irradiation is a green anti-irradiation approach for the betterment of human beings without high cost, side effects and toxicity.

감성돔, Acanthopagrus schlegeli 배의 생존과 부화에 미치는 동해방지제의 영향 (Effects of Cryoprotectants on Survival and Hatching of Black Seabream, Acanthopagrus schlegeli Embryos)

  • 임한규;장영진;조필규
    • 한국양식학회지
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    • 제16권4호
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    • pp.262-266
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    • 2003
  • 어류 배의 냉동보존 방법을 개발하기 위한 연구의 일환으로 감섬돔, Acanthopagrus schlegeli의 초기 배를 대상으로 동해방지제인 DMSO, ethylene glycol 및 glycerol의 최적 농도와 처리시간을 파악하기 위한 연구가 수행되었다. 동해방지제의 적정 농도를 평가하기 위하여 배의 사망률, 부화율 및 반수치사 농도를 조사하였다. 동해방지제로 처리된 감성돔 배의 사망률은 침지농도나 시간과 밀접히 연관되었으며, 감성돔 배에 대한 독성은 DMSO, ethylene glycol, glycerol의 순서로 낮았다. 배의 사망률, 부화율 및 반수치사농도에 대한 결과로부터 감성돔 배를 냉동보존하기 위한 가장 적합한 동해방지제는 DMSO였으며, 다음이 ethylene glycol이었다. 20분의 처리시간에서 효과적인 DMSO의 침지 농도는 2.0∼2.25 M이었으며, ethylene glycol의 경우 1.0∼1.78 M이었다.

Technical Evaluation of Engineering Model of Ultra-Small Transmitter Mounted on Sweetpotato Hornworm

  • Nakajima, Isao;Muraki, Yoshiya;Mitsuhashi, Kokuryo;Juzoji, Hiroshi;Yagi, Yukako
    • Journal of Multimedia Information System
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    • 제9권2호
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    • pp.145-154
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    • 2022
  • The authors are making a prototype flexible board of a radio-frequency transmitter for measuring an electromyogram (EMG) of a flying moth and plan to apply for an experimental station license from the Ministry of Internal Affairs and Communications of Japan in the summer of 2022. The goal is to create a continuous low-dose exposure standard that incorporates scientific and physiological functional assessments to replace the current standard based on lethal dose 50. This paper describes the technical evaluation of the hardware. The signal of a bipolar EMG electrode is amplified by an operational amplifier. This potential is added to a voltage-controlled crystal oscillator (27 MHz, bandwidth: 4 kHz), frequency-converted, and transmitted from an antenna about 10 cm long (diameter: 0.03 mm). The power source is a 1.55-V wristwatch battery that has a total weight of about 0.3 g (one dry battery and analog circuit) and an expected operating time of 20 minutes. The output power is -7 dBm and the effective isotropic radiated power is -40 dBm. The signal is received by a dual-whip antenna (2.15 dBi) at a distance of about 100 m from the moth. The link margin of the communication circuit is above 30 dB within 100 m. The concepts of this hardware and the measurement data are presented in this paper. This will be the first biological data transmission from a moth with an official license. In future, this telemetry system will improve the detection of physiological abnormalities of moths.

Single-Dose Toxicity Study of Intramuscular Neuralgia-Pharmacopuncture Injection in Rats

  • Ji Hye Hwang
    • 대한약침학회지
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    • 제26권4호
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    • pp.348-356
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    • 2023
  • Objectives: Neuralgia-pharmacopuncture (NP) was recently developed as a water-soluble type of pharmacopuncture inspired by CS (care special pain)-pharmacopuncture. I aimed to evaluate the toxic response and approximate lethal dose of when NP when administered intramuscularly to Sprague Dawley rats. Methods: The experimental group was divided into the NP test substance group and the saline control group and administered at a dose of 1.0 mL/animal to the posterior thigh muscles on both sides using a 1 mL syringe; each group consisted of five males and five females. Each rat was monitored for clinical signs and changes in body weight for 14 days after a single intramuscular injection. After completing observation, necropsy findings and localized tolerance at the injection site were assessed via gross necropsy and histopathological examination. Results: No deaths occurred in the NP or control group, regardless of sex. During the observation period, no changes (such as general symptoms, weight change, or visual observation results at the time of autopsy) were judged to be due to the test substance. Histopathological examination showed no changes at the administration site judged to be caused by the test substance in either the male or female test substance administration groups. In addition, mononuclear cell infiltration of the outer membrane of the femoris muscle at the administration site was observed at the same frequency and extent in the control and NP groups, and was judged to be caused by physical stimulation by the injection needle; therefore, it had no toxicological significance. Conclusion: Based on the above results, the approximate lethal dose for a single intramuscular administration of the test substance NP in Sprague-Dawley rats was judged to be > 1.0 mL/animal, and there were no findings that were judged to be due to the test substance at the administration site.

조경산(調經散)과 천금조경탕(千金調經湯)의 효능(效能)에 대(對)한 실험적(實驗的) 연구(硏究) (Studies on the Effects of Chokyungsan and Chunkeumchokyungtang)

  • 김철원
    • 한국한의학연구원논문집
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    • 제1권1호
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    • pp.521-540
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    • 1995
  • To elucidate the effects of Chokyungsan and Chunkeunchokyungtang, after oral administration of Chokyungsan and Chunkeunchokyungtang water extract in mice and rats, acute toxicity, analgesic, sedative, esoogenic actions, action on isolated uterine muscle were measured. The rlesults obtained were as follows: 1. The yield of water extract of Chokyungsan and Chunkeunchokyungtang was 24.5%, 32.2%, minimum lethal dose was 4,000mg/kg, which rarely had the acute toxicity in mice and rats. 2. The analgesic effects of Chokyungsan and Chunkeunchokyungtang by acetic acid induced writhing syndrome in mice were not remarkaely observed. 3. The relaxant action of Chokyungsan on on oxytocin induced contracted uterine muscle in estrogenized rats were not remarkably observed, but Chunkeunchokyungtang were remarked. 4. The sedative effects of Chokyungsan and Chunkeunchokyungtang by hexobabital sodium induced sleeping time in mice. 5. administration of Chokyungsan and Chunkeunchokyungtang caused remarkable increase in weight of rat's uterus.

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Mercuric Chloride가 붕어(Carassius auratus)에 미치는 급성독성 및 축적에 관한 연구 (A Study on the Acute Toxicity and Accumulation of Mercuric Chloride to Goldfish (Carassius auratus))

  • 이재형
    • 한국환경보건학회지
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    • 제15권2호
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    • pp.97-106
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    • 1989
  • This experiment was performed to study the acute toxic effects of mereuric chloride(HgCl$_{2}$) in goldfish (Carassius aurams). In the study, Lc$_{50}$ values were determined for each 24, 48, 72 ,and 96-hr and mercury bioassay during the tests were performed. in five parts gill, kidney, liver, muscle and egg. The results isummarized were as follows 1. In the range of acute lethal toxicity for goldfish was 0.15-1.50 mg/l and the Lc$_{50}$ values decreased with exposure time. 2. The Lc$_{50}$ values of HgCl$_{2}$ for goldfish at 24, 48, 72 and 96 hour were 0.64, 0.53, 0.46, and 0.39 mg/l, respectively. 3. In the 400 $\mu$g/l treatment group, the average levels of mercury residues in the gill, kidey, liver, muscle and egg during 96 hour were 107.02 $\mu$g/g, 8.65 $\mu$g/g, 6.87 $\mu$g/g, 0.61 $\mu$g/g, and 0.82 $\mu$g/g, respectively. 4. The mercuny residues of gill was up to 12-175 times greater than mercury contents found in the other tissues.

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국내 공항 구조 및 소방 업무 개선방안 연구 (A Study on Improvement of Domestic Airport Service for Rescue and Fire Fighting)

  • 한재현;정기연
    • 한국항공운항학회지
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    • 제16권4호
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    • pp.69-74
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    • 2008
  • Aircraft fires due to accident at an airport may be under a special situation. An outstanding characteristic of aircraft fires is their tendency to reach lethal intensity within a very short time. In domestic aviation act, there are regulations related to services coping with the aircraft accidents within an airport. To cope aircraft fires, it is necessary to define clearly the regulations and standards about the services and related activities of rescue and fire fighting, and to keep the regulations and standards. The study has been performed on the basis of International Civil Aviation Organization (ICAO) Airport Services Manual of rescue and fire fighting. The objective of study is to suggest improvement methods for standards applicable to actual service practices of rescue and fire fighting by analyzing through the comparison of domestic and international regulations and standards.

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소규모 건설현장의 중대재해 저감 방안 도출을 위한 연구 (A Study of Decreasing Critical Disaterous Accidents in Small Construction Sites)

  • 백신원;김한중;최돈흥
    • 한국농공학회논문집
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    • 제54권6호
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    • pp.121-131
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    • 2012
  • Many of the falling which is the number one risk factor in lethal accidents in construction could have been prevented if the right activity or supervising had been taken in time. All other measures do not preventive the fall, but rather intercept the fallen itself or preventive severe injury. The most common and the bets measures on the preventive measures are guardrails which are to be worn on the site. Workers always exposed the risk of serious accidents induced by causal effects related with environments around construction sites. In order to represent how to decrease the risk of workers, this study was accomplished with a number of interview with experienced site director, cheief of instructors, workers. And the questionaire survey (2012. 5~2012. 10) were used to make proposed policies which are expected to reduce critical disastrous accidents and strength authorized limits of director's management automatically.