• 제목/요약/키워드: LD 50

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Basic Physiological Research on the Wing Flapping of the Sweet Potato Hawkmoth Using Multimedia

  • Nakajima, Isao;Yagi, Yukako
    • Journal of Multimedia Information System
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    • 제7권2호
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    • pp.189-196
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    • 2020
  • We have developed a device for recording biological data by inserting three electrodes and a needle with an angular velocity sensor into the moth for the purpose of measuring the electromyogram of the flapping and the corresponding lift force. With this measurement, it is possible to evaluate the moth-physiological function of moths, and the amount of pesticides that insects are exposed to (currently LD50-based standards), especially the amount of chronic low-concentration exposure, can be reduced the dose. We measured and recorded 2-channel electromyography (EMG) and angular velocity corresponding to pitch angle (pitch-like angle) associated with wing flapping for 100 sweet potato hawkmoths (50 females and 50 males) with the animals suspended and constrained in air. Overall, the angular velocity and amplitude of EMG signals demonstrated high correlation, with a correlation coefficient of R = 0.792. In contrast, the results of analysis performed on the peak-to-peak (PP) EMG intervals, which correspond to the RR intervals of ECG signals, indicated a correlation between ΔF fluctuation and angular velocity of R = 0.379. Thus, the accuracy of the regression curve was relatively poor. Using a DC amplification circuit without capacitive coupling as the EMG amplification circuit, we confirmed that the baseline changes at the gear change point of wing flapping. The following formula gives the lift provided by the wing: angular velocity × thoracic weight - air resistance - (eddy resistance due to turbulence). In future studies, we plan to attach a micro radio transmitter to the moths to gather data on potential energy, kinetic energy, and displacement during free flight for analysis. Such physiological functional evaluations of moths may alleviate damage to insect health due to repeated exposure to multiple agrochemicals and may lead to significant changes in the toxicity standards, which are currently based on LD50 values.

Salmonella Typhimurium의 돼지 호중구내 연속노출에 따른 특성변화 (Changes of characterization of Salmonella Typhimurium isolate following sequential exposures to porcine neutrophil)

  • 이희수;김애란;윤민;이지연;임숙경;강호영;유한상;박중원;위성환;정석찬
    • 대한수의학회지
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    • 제53권1호
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    • pp.29-35
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    • 2013
  • To develop a live vaccine candidate using an attenuated strain of Salmonella Typhimurium (ST), biochemical properties, plasmid profile, PFGE patterns and pathogenic analysis of the ST isolate were carried out after sequential passage of the ST isolate in porcine neutrophils. By the passage, the ability of the neutrophil-adapted isolate to utilize d-xylose was lost, while the ability of the strain to ferment trehalose was delayed after 2 or more days of the culture. Also, changes including deletion of the gene fragments were observed in PFGE analysis of the neutrophil-adapted isolates. Two plasmids, 105kb and 50kb, were cured in the strain passaged over 15 times in porcine neutrophils. The 50% of lethal dose ($LD_{50}$) of the parent strain was changed from $1{\times}10^5\;LD_{50}$ to $6{\times}10^6\;LD_{50}$ by the passage in intraperitoneal injection of the strains into mice. These results suggested that bacterial genotypic and phenotypic responses might be globally altered depending on the inside environment of neutrophils.

웅성불임기술을 이용한 쇠파리 구제에 관한 연구 (4) 방사선 조사가 쇠파리에 미치는 영향 (Study on Stable Fly Eradication by Sterile-male Technique (4) Effects of X-ray Irradiation on the Stable Fly)

  • 정규회;유준;권신한
    • 한국응용곤충학회지
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    • 제14권3호
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    • pp.163-166
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    • 1975
  • 쇠파리의 난과 3-5일령 및 7-9일령 용에 X-선을 조사시켜 부화율, 우화율을 조사하였으며 또한 3-5일 영용에 X-선을 조사시켜 우화된 성충의 불임유기선량에 대한 실험결과를 다음과 같이 얻었다. 1. 란부화율은 약 300R 조사시 $50\%$이었으며 3-5일영 및 7-9일영 번데기에 대한 사충율의 회귀직선은 Y=2.665x+2.301, Y=4.36x_0,18이고 중앙치사선량$(LD_{50})$은 11.5KR과 12.6KR이었다. 2. 3KR 조사웅충과 정상자충에서 산란된 란은 약 $98\%$가 미부화되었다. 그러나 2.KR 조사자충과 정상웅충 사이에서 산란된 란은 $100\%$가 부화되지 않았다. 3. 불임유기선량은 자충이나 웅충과 같이 4KR이면 완전할 것으로 보며 $(LD_{50})$선량을 고려할 때 충분히 이용가능할 것으로 본다.

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랫드에 대한 KDRD-002의 급성경구독성시험 (Acute Oral Toxicity of KDRD-002 in Rats)

  • 김형식;이승기;김규봉;곽승준;안미영;최병천;이병무
    • Biomolecules & Therapeutics
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    • 제4권4호
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    • pp.310-313
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    • 1996
  • Acute oral toxicity studies of KDRD-002 (Coriolus versicolor polysaccharide :DDB= 19.2:1) were carried out in Sprague-Dawley rats of both sexes. In this study, we daily examined number of deaths, clinical signs, body weights and pathological examinations for 7 days after single oral administration of KDRD-002 with different dose levels. KDRD-002 did not show any toxic effect in rats and oral LD$_{50}$ value was over 3.25 g/kg in rats.s.

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주요우울장애 환자의 증상 심각도에 따른 신경인지적 특성 (Neurocognitive Characteristics According to Depression Severity in Patients with Major Depressive Disorder)

  • 황선희;이헌정;김명선
    • 생물정신의학
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    • 제24권3호
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    • pp.149-154
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    • 2017
  • Objectives This study investigated associations between symptom severity and neurocognitive functions in patients with major depressive disorder using comprehensive neuropsychological tests. Methods Ten patients with low depression (LD) and 22 patients with high depression (HD) participated. Symptom severity was determined by both the Beck Depression Inventory and the Hamilton Depression Rating Scale. Additionally, anxiety was measured by the Korean version of the State-Trait Anxiety Inventory (STAI-KYZ). Ten subtests of the Korean-Wechsler Adult Intelligence scale (K-WAIS), Stroop test, the word/design fluency tests were administered to assess cognition. Results The LD and HD groups did not differ in any of cognitive measures but anxiety level. Namely, the HD group obtained significantly higher scores on the state (U = 29.50, p < 0.01) and trait (U = 28.50, p < 0.001) anxiety scales than the LD group. A significant interaction effect between trait anxiety and depression severity was observed on the picture arrangement subtest of the K-WAIS [F (1, 27) = 5.09, p < 0.05]. Conclusions Cognitive deficits observed in patients with major depressive disorder may be related to other factors rather than current symptom severity. Trait anxiety possibly moderates the effect of current symptom severity on social judgment in these patients.

Expandable Polystyrene Box의 '신고' 배의 신선도 유지효과 (Freshness Extension of 'Shingo' Pear Packed with Expandable Polystyrene Form Box)

  • 박형우;박종대;김동만;이명훈
    • 한국포장학회지
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    • 제4권2호
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    • pp.12-17
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    • 1998
  • 개발한 EPS 포장상자가 농산물의 신선도 유지효과 기능이 있는지의 여부를 분석코자 배를 포장하여 $20^{\circ}C$에 저장하면서 골판지상자와 0.02와 0.04mm 두께의 LDPE필름으로 포장한 것들과 신선도 유지효과를 비교하였다. 저장 50일 후 중량 감소는 대조구는 4.4%, EPS 상자는 0.7%의 중량감소가 나타났고, 비타민C도 2.12와 2.63 mg%로 EPS 포장구가 20% 높게 유지되고 있었다. 당도와 산도는 포장구간에 큰 차이가 있었으며 부패는 대조구는 상자당 1-2개과가 발생했으나 EPS 포장구는 발생하지 않아 개발한 EPS 포장구를 신선도 유지를 위한 유통용 상자로 활용가능성이 확인되었다.

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비트 주파수를 스위칭할 수 있는 듀얼 모드 외부 공진기 레이저 (Beat Frequency Switchable Dual-mode External cavity laser)

  • 김철섭;김륜경;이경식;송정환;오윤경
    • 한국광학회지
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    • 제17권6호
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    • pp.489-492
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    • 2006
  • 평판도파로 상에 FP-LD와 샘플격자를 하이브리드 집적하여 듀얼 모드로 발진하는 외부 공진기 레이저를 구현하였다. 샘플격자에 인가되는 전류를 50mA에서 55mA로 변화시킴으로써 듀얼 모드간의 beat 주파수를 132GHz에서 406GHz로 스위칭할 수 있었다.

Electroabsorption modulator-integrated distributed Bragg reflector laser diode for C-band WDM-based networks

  • Oh-Kee Kwon;Chul-Wook Lee;Ki-Soo Kim
    • ETRI Journal
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    • 제45권1호
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    • pp.163-170
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    • 2023
  • We report an electroabsorption modulator (EAM)-integrated distributed Bragg reflector laser diode (DBR-LD) capable of supporting a high data rate and a wide wavelength tuning. The DBR-LD contains two tuning elements, plasma and heater tunings, both of which are implemented in the DBR section, which have blue-shift and red-shift in the Bragg wavelength through a current injection, respectively. The light created from the DBR-LD is intensity-modulated through the EAM voltage, which is integrated monolithically with the DBRLD using a butt-joint coupling method. The fabricated chip shows a threshold current of approximately 8 mA, tuning range of greater than 30 nm, and static extinction ratio of higher than 20 dB while maintaining a side mode suppression ratio of greater than 40 dB under a window of 1550 nm. To evaluate its modulation properties, the chip was bonded onto a mount including a radiofrequency line and a load resistor showing clear eye openings at data rates of 25 Gb/s nonreturn-to-zero and 50 Gb/s pulse amplitude modulation 4-level, respectively.

Terbufos가 병아리 중(中) Acetylcholinesterase에 미치는 영향(影響) (Effect of Terbufos on the Activity of Acetylcholinesterase in the Chicken)

  • 홍종욱;김정호;김장억
    • Applied Biological Chemistry
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    • 제29권3호
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    • pp.324-330
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    • 1986
  • Terbufos가 병아리 중(中) brain Ach-E 및 plasma Ch-E 활성(活性)에 미치는 영향(影響)을 조사한 결과(結果)는 다음과 같았다. Terbufos의 병아리에 대(對)한 급성경구(急性經口) $LD_{50}$은 1.82mg/kg이었다. Brain Ach-E와 plasma Ch-E에 대(對)한 $pI_{50}$과 Ki는 Terbufos$LD_{50}$에서는 Brain Ach-E 활성(活性)이 83%, plasma Ch-E 활성(活性)이 94%가 저해(沮害)되었다.

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MOCVD를 이용한 GaAs/AlGaAs GRIN-SCH 양자 우물 레이저의 제작 및 특성 (Fabrication and Characteristics of GaAs/AlGaAs GRIN-SCH Quantum Well Laser Diode by MOCVD)

  • 손정환
    • 한국광학회:학술대회논문집
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    • 한국광학회 1991년도 제6회 파동 및 레이저 학술발표회 Prodeedings of 6th Conference on Waves and Lasers
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    • pp.139-143
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    • 1991
  • GRIN-SCH quantum well structured Laser Diode were fabricated using MOCVD and operated as CW at room temperature. The threshold current density of the LD with 670${\mu}{\textrm}{m}$ cavity length was 530 A/$\textrm{cm}^2$. For the ridge waveguide type index guiding structured LD with 6${\mu}{\textrm}{m}$ stripe width and 240${\mu}{\textrm}{m}$ cavity length, the threshold current was 50㎃. The maximum differential quantum efficiency was 0.95W/A when the optical output was 60mW. The lasing wavelength of QW LD was 865nm. In the L-I measurement. TE mode was superior to TM mode. From the near field pattern, single lateral mode operation was observed.

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