• Title/Summary/Keyword: LD

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Toxicological Evaluation of Median Lethal Dose $(LD_{50})$ ($LD_{50}$의 독성학적 고찰)

  • 박현선;홍채영;오진아;윤승천;이병무
    • Toxicological Research
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    • v.12 no.2
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    • pp.143-154
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    • 1996
  • This paper reviews the toxicological role of median lethal dose ($LD_50$) based on animal and human data. Animal oral $LD_50$ values of eighty seven chemicals were collected and comparatively evaluated with human minimum toxic dose ($TD_50$). In general, animal $LD_50$ values were much higher than human $TD_50$. The ratios between $LD_50$ and TDlo were ranged from 0.01 and over 1000, suggesting safety factor of up to 1000 between humans and animals in the case of acute toxicity data. However, about 40% of chemicals investigated were within the ratio of 10. Although the cases (N=20) were small, $LD_50$ values of guinea pig were closer to human TDlo than those of other animal species. In interanimal species (rat, mouse, rabbit, dog), the ratios of $LD_50$ values were between 0.1 and 5 (up to 50-fold difference). When the data are analyzed by chemical strut-ares, human $TD_50$ values were very close to rat oral $LD_50$ values. These data suggest that rat oral $LD_50$ value might be a useful parameter predicting human TDlo and one animal species could be sufficient for acute toxicity test.

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Design and Implementation of LD Publication Engine to Support Various Teaching and Learning Methods (다양한 교수-학습 방법을 지원하는 LD Publication 엔진의 설계 및 구현)

  • Kim, Young-Keun;Lee, Chang-Hun;Roh, Jin-Hong
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.5
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    • pp.606-610
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    • 2010
  • In order to provide effective studies in accordance with the shifts in learning paradigms, an LD Publication engine, which is the former engine from the Learning Design (LD) based learning management system, was designed and implemented. The LD Publication engine analyzes the learning contents packages that have been prepared based on the LD and analyzes the constructions and meanings of the information files that describe learning activities in order to model them. The modeled data are fragmentized into effective and accessible forms from in the learning management systems and are then put into the database. LD based learning management systems provide learning effects and learner convenience designed to provide learners with a high performance learning platform. In addition, they will activate the development of content through the reproduction, reuse and sharing of the learning content, which will contribute to the expansion of infrastructures. These systems are also designed to enable linkages among learners' competences, preferences and portfolio, and thus the systems can be easily expanded.

Simultaneous modulation of digital/SCM signal using a single LD for broadcasting in PON based optical access network (PON 기반 광가입자망에서 방송 신호 전송을 위한 단일 LD을 이용한 디지털/SCM 신호 동시 변조기술)

  • Kim Tae-Young;Kim Kyung-Hyun;Han Sang-Kook
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.5 s.347
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    • pp.1-6
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    • 2006
  • By comparing video-overlay method where digital and SCM signal are modulated in different optical source, we experimentally investigated the performance of simultaneous modulation of data and broadcasting signals using a single LD for broadcasting in PON based optical access network. The experimental results show that by increasing the minimum value of injected current for LD modulation above about 1.5 times of threshold current of LD, data and broadcasting signals can modulate without mutual interference. We also proposed and demonstrated the scheme of optical transmitter optimized for simultaneous modulation of data and broadcasting signals where anode and cathode of LD are separately used as signal interface for data and broadcasting signals, respectively.

Extra-LDH Isoenzyme($LD_6$) in Myocardial Infarction with Serious Course - Two cases report - (예후가 불량한 심근경색환자에 나타난 혈청 LD Isoenzyme의 Extra Band($LD_6$) - 2 증례 보고 -)

  • Kim, Kyung-Dong;Choi, Myung-Sook;Lee, Chae-Hoon;Jeon, Chang-Ho;Kim, Chung-Sook;Kim, Young-Jo
    • Journal of Yeungnam Medical Science
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    • v.5 no.2
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    • pp.247-254
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    • 1988
  • Serum lactate dehydrogenase isoenzymes are separated 5 fractions($LD_1-LD_5$) in normal serum by agrose electrophoresis. An unusual band on the cathodic side of $LD_5$ isoenzyme has been found on lactate dehydrogenase electrophores is of serum, called $LD_6$, and the presence of which signifies a poor prognosis for the patients of myocardial infarction. In recent, we have experienced $LD_6$ in two patients with myocardial infarction. Cardiac arrest was noted within 24 hours after exhibition of $LD_6$ extraband and they did not recover from their illness.

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The fabrication of InGaAsP/InP RWG(ridge waveguide) MQW-LD by the vertical LPG system (수직형 LPE장치를 이용한 InGaAsP/InP RWG(Ridge Waveguide) MQW-LD제작)

  • 박윤호;오수환;하홍춘;안세경;이석정;홍창희;조호성
    • Korean Journal of Optics and Photonics
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    • v.7 no.2
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    • pp.150-156
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    • 1996
  • RWG MQW-LD has been made with our vertical LPE system from the optimal design condition for the RWG MQW-LD to be activated as weakly index-guided LD. Through several experiments we have established the growth condition which can be used through to grow the MQW-DH wafer and to control the thickness of MQW layer to ~200$\AA$. 4 ${\mu}{\textrm}{m}$-thickness of the ridge pattern has been formed through the photolithographic process on the MQW-DH wafer grown by the former condition, and then we have fabricated the RWG MQW-LD using it. From the result of measuring the electro-optical characteristics we can make sure that it can be lasing as lasing as laterally single mode at even more than $2.7I_{th}$.

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Sensory Characteristics of Doenjang with Added Licorice Powder as Assessed by Response Surface Methodology (반응표면분석법을 이용한 감초분말 첨가 된장의 관능적 특성)

  • Kim, Mi-Lim;Park, Eun-Jung;Jeong, Ji-Suk
    • Korean journal of food and cookery science
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    • v.26 no.1
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    • pp.62-71
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    • 2010
  • The followings describes the result of making doenjang with added licorice (Glycyrrhiza uralensis) powder. and investigating its sensory characteristics and physicochemical quality. General preference was high at 20% salinity and 2% licorice (LD204), and 16% salinity and 2% licorice (LD162). The moisture content was unchanged in the control group, while it was reduced in LD204 and LD162 in the first week of fermentation, but showed little change after then. pHs were all in the range 5.90~5.97 on day 0, but decreased from 5.90 to 5.72 in the control group in the fifth week. LD204 changed from 5.95 on day 0to 5.42 in the first week, and then it gradually increased again and became 5.93 in the fifth week, which was similar to that of day 0. LD162 was 5.97 on day 0 and showed cyclic slight increases and decreases in the first week. It increased to 6.32 in the fifth week, which was higher than that of day 0 that is, its pH was higher than that of LD204. The acidity showed a difference right after it was made. In the control group, lactic acid content gradually increased from 0.16% on day 0 to the highest, 0.59%, in the fourth week. It slightly decreased in the fifth week. LD204 slowly increased from 0.25% on day 0 to a maximum, 0.50%, in the fourth week. It also slightly decreased in the fifth week, quite similarly to that of the control group. LD162, gradually increased from 0.22% on day 0 to the highest, 0.49, in the third week, and decreased after the fourth week. Salinity was 29.5%, 22.0%, and 18% in each of the control group, LD204, and LD162 on day 0 but increased to 34.0%, 29.0%, and 26.0% in the fifth week. Soluble solid was $32^{\circ}Brix$, $28^{\circ}Brix$, and $26^{\circ}Brix$ in each of the control group, LD204, and LD162 on day 0, but slightly increased to $40^{\circ}Brix$, $32^{\circ}Brix$, and $30^{\circ}Brix$ on the fifth day. It is thought that because of the sweetness of licorice, the higher-salinity doenjang earned a higher sensory test score than that of traditional doenjang. If its salinity is lowered a little, it could be used as a sauce, even possibly having medical effects as well.

Implementation of Run-time Engine supporting cooperative learning based on IMS LD specification (IMS LD 표준에 기반한 협력학습을 지원하는 실행 엔진의 구현)

  • Lee, Chang-Hun
    • Proceedings of the Korean Information Science Society Conference
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    • 2011.06b
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    • pp.266-268
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    • 2011
  • 최근 이러닝의 발전과 함께 다양한 표준들이 주목받고 있으며 그중에서도 SCORM 표준은 자기 주도적 학습 중심에 초점을 두고 있으므로 협력학습을 지원하기 위해서는 외부 도구를 별도로 이용해야 한다. 하지만 IMS LD 표준에서는 협력 학습을 지원하기 위해 컨퍼런스 서비스를 이용하여 콘텐츠를 저작할 수 있으며, 컨퍼런스 서비스는 LD 실행 엔진에 포함되어 실행되거나 외부 도구로 실행될 수 있도록 유연성을 제공한다. 이에 본 논문에서는 LD 표준에 기반하여 협력 학습을 실행 엔진 내부에서 지원할 수 있도록 개발된 내용에 대하여 설명할 것이다. 개발된 LD 실행 엔진은 LD 표준을 준수하며, LD 콘텐츠에 기술된 협력 학습 설계 내용에 따라 협력 학습을 진행할 수 있어 설정된 역할에 따라 협력 학습에서의 권한을 달리하여 협력 학습을 진행할 수 있다는 특징을 가지고 있다.

Prevention of Cholesterol Gallstone Formation by Lactobacillus acidophilus ATCC 43121 and Lactobacillus fermentum MF27 in Lithogenic Diet-Induced Mice

  • Oh, Ju Kyoung;Kim, You Ra;Lee, Boin;Choi, Young Min;Kim, Sae Hun
    • Food Science of Animal Resources
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    • v.41 no.2
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    • pp.343-352
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    • 2021
  • The objective of this study was to evaluate the effects of Lactobacillus acidophilus ATCC 43121 and L. fermentum MF27 on biochemical indices in the serum, cholesterol metabolism in the liver and mucin expression in the gallbladder in lithogenic diet (LD)-induced C57BL/6J mice to determine the preventive effects of lactobacilli on gallstone formation. By the end of 4 wk of the experimental period, mice fed on a LD with high-fat and high-cholesterol exhibited higher levels of total and low-density lipoprotein cholesterol in the serum compared to mice fed on control diet or LD with L. acidophilus ATCC 43121 (LD+P1; p<0.05). Cholesterol-lowering effects observed in the LD+P1 and LD with L. fermentum MF27 (LD+P2) groups were associated with reduced expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase in the liver compared to the LD group (p<0.05). Furthermore, expression of the gel-forming mucin, including MUC5AB and MUC5B, was suppressed in the LD+P1 and LD+P2 groups compared to the LD group (p<0.05). Therefore, steady intake of both L. acidophilus ATCC 43121 and L. fermentum MF27 may have the ability to prevent the formation of cholesterol gallstones in LD-induced C57BL/6J mice.

Anatomical Study of the Close Association between Latissimus Dorsi and Surrounding Muscles. How to Safely Harvest the Muscle?

  • Oh, Sangho;Kim, Hyunju;Lee, Jae-Ho;Son, Daegu
    • Archives of Plastic Surgery
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    • v.49 no.5
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    • pp.596-603
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    • 2022
  • Background We suggested an easy and effective harvesting technique to avoid injury to tissues adjacent to the latissimus dorsi (LD). Methods Between 2007 and 2017, breast reconstruction was performed with an LD flap using the "bottom-up" technique. Medical records were retrospectively reviewed. Data on postoperative complications, results, and follow-up were obtained. Nine cadaveric dissections were performed to assess positional relationships between LD and adjacent muscles based on the ribs where relevant muscles and LD attach. Overall, 78 LD flaps were harvested without complications. Results Average age was 45.4 years. The mean operation time was 260minutes. There were no abnormalities or injuries in the adjacent fascia and muscles during the flap harvest. Drains were removed at an average of 21.9 days postoperatively. In all cadavers, there was conjoined fascia between the thoracolumbar and LD fasciae. The average level of the merging point between the LD and external oblique muscle (EOM) was 8.9 to 11.1 ribs. The average level of the overlapping point between the LD and serratus posterior inferior (SPI) was 9.5 to 11.1 ribs. Conclusions There are three dangerous zones during LD flap harvesting. The first zone is where the conjoined fascia encompasses the LD and thoracolumbar fasciae. The second zone is where the LD merges with the EOM and the serratus anterior. The third zone is the lower part where the LD merges with the SPI and EOM. The "bottom-up" technique enables a more meticulous and atraumatic operation by beginner flap surgeons.

COMPARISON OF MEMORY FUNCTION BETWEEN ATTENTION DEFICIT/HYPERACTIVITY DISORDER AND LEARNING DISORDER CHILDREN (주의력 결핍/과잉운동 장애와 학습 장애 아동의 기억 기능 비교)

  • Kim, Yong-Hee;Cho, Soo-Churl;Shin, Min-Sup
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.13 no.1
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    • pp.85-92
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    • 2002
  • Objectives:This study was conducted to compare the memory function among the attention deficit/hyperactivity disorder(ADHD), the learning disorder(LD) and the comorbidity disorder(ADHD+LD) groups. Methods:Thirty-four children(11 ADHD, 5 LD, 9 ADHD+LD, and 8 Psychiatric control) were individually assessed using the KEDI-WISC and Memoty Assessment Scale(MAS), and then the results of those test were analyzed. Results:In memory test, all of three group showed lower performances than control group. The comorbidity, the LD and the ADHD group showed lower scores in almost subtests of MAS respectively. The good performance in memory test was significantly correlated with the types of memory strategy and error response children used during testing. Discussion:The clinical utility of the memory test like MAS was discussed in terms of differential diagnosis for ADHD, LD and ADHD+LD children.

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