• Title/Summary/Keyword: LEEM

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Technological Trend of Mid-infrared Optical Sensors (중적외선 광센서 기술동향)

  • Leem, Y.A.;Kwon, O.K.;Kim, K.
    • Electronics and Telecommunications Trends
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    • v.33 no.6
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    • pp.41-49
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    • 2018
  • Mid-infrared optical sensors have a number of compelling advantages for remote sensing and the simultaneous measurement of mixtures. However, they still have difficulties in accurate detection owing to signal interferences among a large number of molecular fingerprints in the mid-infrared band, which result in very slow commercialization. Higher sensitivity and higher selectivity are required to overcome this obstruction in measurement technology. In this paper, we review and analyze the trends of mid-infrared sensor technologies enhancing the sensitivity and selectivity.

Novel Synthesis of Imidazo[1,2-b]Pyrazoles and Their Fused Derivatives

  • Sherif, Sherif-M.;Hussein, Abdel-HaLeem-M.;El-kholy, Yehya-M.
    • Archives of Pharmacal Research
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    • v.17 no.5
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    • pp.298-303
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    • 1994
  • 4-Arylazo-1H-pyrazol-3, 5-idimines 1a-c reacted with bromomalononitrile (2) to yield the corresponding imidazo[1, 2-b]pyrazoles 3a-c. The latter reacted with some active methylene compounds and with .alpha.-cinnamonitriles to afford the corresponding pyrazoloimidazopyridines 6, 8, 9 and 15, respectively. Compounds 3 reacted with each of formic acid, formamide, trichlo-roacetonitrile and with guanidine to yield the corresponding pyrazoloimidazopyrimidines 16-19 respectively.

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Detection of SNPs involved in the development of asthma with genetic algorithms (유전 알고리즘을 이용한 천식과 단일염기다형성(SNP)의 연관성)

  • Leem, Sang-Seob;Kim, Seung-Hyun;Wee, Kyu-Bum
    • Proceedings of the Korea Information Processing Society Conference
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    • 2007.05a
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    • pp.605-608
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    • 2007
  • 천식(Asthma)과 같은 복합질환(Complex Disease)의 원인과 작용 모델을 찾기 위해서 여러가지 통계적인 방법들과 기계 학습(Machine Learning)의 방법 등이 사용되고 있다. 본 연구에서는 유전 알고리즘을 이용하여 천식 환자와 대조군들을 분류할 수 있는 단일염기 다형성(SNP, Single Nucleotide Polymorphism)의 조합에 대하여 조사한다.

Effects of L-NAME on the Mechanical Hyperalgesia after the Development of Inflammation by Freund's Complete Adjuvant in Rat Paw (FCA에 의한 염증 유발 후 주입된 L-NAME이 기계적 통각과민에 미치는 영향)

  • Kim, Min-Kyung;Choi, Yoon;Kong, Hyun-Seok;Leem, Joong-Woo;Leem, Hang-Soo;Chung, Soo-Jin;Lee, Cheong
    • The Korean Journal of Pain
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    • v.12 no.2
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    • pp.171-176
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    • 1999
  • Background: Effect of nitric oxide on the hyperalgesia induced by inflammation is controversial. From our previous experiment, NOS inhibitor, L-NAME given during the induction period decrease mechanical hyperalgesia occured by Freund's complete adjuvant induced inflammation. In addition, we attempted to analyze the effects of L-NAME on mechanical hyperalgesia after the development of inflammation by Freund's complete adjuvant in rat paw. Methods: Male Sprague Dawley rats were divided into four groups; control (normal saline), and three different doses of L-NAME (0.1 mg, 1 mg, 10 mg). Inflammation was induced in rats by injecting 0.15 ml of Freund's complete adjuvant (FCA) intraplantarly. Rats showed typical hyperalgesia within twelve hours after injection and maintained this for about one week. Tests were done 2 days after injection of FCA. After the baseline test either L-NAME or saline was injected under light halothane anesthesia. Effect of L-NAME on hyperalgesia was assessed by measuring mechanical hyperalgesia at 15, 30, 60, 90, 120 minutes. Same experients were repeated on normal rats. Results: When injected at the site of inflammation, L-NAME caused dose dependent decrease in mechanical hyperalgesia. However, normal rats also showed increased mechanical threshold after L- NAME injection. Conclusions: Although L-NAME reduces FCA induced mechanical hyperalgesia, this result may solely be due to inhibition of nitric oxide production and need to be further determined.

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Central Pain from Excitotoxic Spinal Cord Injury Induced by Intraspinal NMDA Injection: A Pilot Study

  • Leem, Yeon-Ju;Joh, Jung-Wha;Joeng, Kyoung-Woon;Suh, Jeong-Hun;Shin, Jin-Woo;Leem, Jeong-Gill
    • The Korean Journal of Pain
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    • v.23 no.2
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    • pp.109-115
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    • 2010
  • Background: The pathophysiological and neurochemical changes following spinal injury are not yet elucidated. This study was designed to evaluate the morphological changes of the dorsal horn of the spinal cord and profiles of pain behaviors following intraspinal injection of NMDA in rats. Methods: Rats were randomized into three groups: a sham-operated control group and groups where the rats received 10 mM or 100 mM N-methyl-D-aspatate (NMDA) injected into their spinal dorsal horn. Following injection, hypersensitivity to cold and mechanical stimuli and excessive grooming behaviors were assessed serially for four weeks. Morphological changes of the spinal cord were evaluated four weeks after intraspinal injection. Results: Few animals in the NMDA groups developed hypersensitivity to cold and mechanical stimuli. The number of groomers and the severity of excessive grooming were significantly higher in the 100 mM NMDA group than those values of the control and 10 mM NMDA groups. The size of the neck region (lamina III-IV) was significantly smaller in the 100 mM NMDA group than in the control and 10 mM NMDA groups. Conclusions: In conclusion, intraspinal injection of NMDA in rats leads to the pathological sequela in the spinal cord and to excessive grooming behavior. These results support the use of NMDA and excessive grooming behavior after excitotoxic SCI as a model to study chronic pain after SCI.

Single Oral Dose Toxicity Test of Jeopgoltang Extracts in Sprague-Dawley Rat (접골탕(接骨湯) 2.0의 Sprague-Dawley 랫드를 이용한 단회경구투여 독성시험)

  • YoungJin Choi;HyoJung Kim;Se-Jin Kim;JunSub Kim;Jiwoon Jeong;HyunHee Leem;BoGyung Jang;YuJin Park;Jungtae Leem;Gi-Sang Bae;Bitna Kweon;Dong-Uk Kim
    • The Korea Journal of Herbology
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    • v.39 no.2
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    • pp.19-25
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    • 2024
  • Objectives : Jeopgoltang (JGT) is a new Korean herbal medicine formulation that is used to treat bone fractures. Although JGT is frequently used in clinical practice, there is a lack of scientific evidence on its safety. This study aimed to evaluate the preclinical toxicity of JGT using a single oral dose toxicity test in Sprague-Dawley (SD) rats. Methods : Five male and female rats per group were orally administered 1,250, 2,500, or 5,000 mg/kg of JGT after fasting for 12 h. Mortality and changes in clinical signs, body weight, and necropsy findings were monitored for 14 days according to the guidelines of the Korean Ministry of Food and Drug Safety and Organisation for Economic Co-operation and Development (OECD). Results : No significant clinical signs or mortality were observed after a single administration of up to 5,000 mg/kg. In addition, no significant necropsy findings related to JGT administration were observed. Conclusions: In conclusion, these results suggest that approximate Lethal Dose (ALD) of JGT on SD rats is over 5,000 mg/kg.

Acetylcholinesterase Inhibitors from the Roots of Angelica dahurica

  • Kim, Dae-Keun;Lim, Jong-Pil;Yang, Jae-Heon;Eom, Dong-Ok;Eun, Jae-Soon;Leem, Kang-Hyun
    • Archives of Pharmacal Research
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    • v.25 no.6
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    • pp.856-859
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    • 2002
  • In the course of finding Korean natural products for acetylcholinesterase (AChE) inhibitory activity, we found that a methanolic extract of the roots of Angelica dahurica showed significant inhibitory effects on AChE. Bioassay-guided fractionation of the methanolic extract resulted in the isolation of three furanocoumarins, isoimperatorin (1), imperatorin (2) and oxypeucedanin (3), as active principles. These compounds inhibited AChE activity in a dosedependent manner, and the $IC_{50}$ values of compounds 1-3 were 74.6, 63.7 and 89.1 uM, respectively.

Isolation of a Bacterium That Inhibits the Growth of Anabaena cylindrica

  • Kim, Chul-Ho;Leem, Mi-Hyea;Choi, Yong-Keel
    • Journal of Microbiology
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    • v.35 no.4
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    • pp.284-289
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    • 1997
  • A Gram (-), rod-shaped bacterium $2.3{\sim}2.8{\times}0.45{\mu}m$ in size which exhibited growth-inhibiting effects against a cyanobacterium (Anabaena cylindrica) was isolated from Daechung Dam Reservoir. This isolate was identified as Moraxella sp. and designated Moracella sp. CK-1. Hollow zones formed around bacterial colonies on the cyanobacterial lawn. In a mixed-culture of A. cylindrica and the isolate, each microorganism grew inverse-proportionally, and the cyanobacterial vegetative cells completely disappeared within 24 hours. On treatment with Moraxella sp. CK-1, cell walls of A. cylindrica disappeared, but sheathes remained in a more electron dense form. The unit membrane such as thylakoidal membrane was stable to bacterial lysing activity. This bacterium showed a broad action spectrum against cyanobacteria. The growth-inhibiting activity of Moracella sp. CK-1 against A. cylindrica is believed to be performed through the excretion of active substances.

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