• Title/Summary/Keyword: horn

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A Study for the SAW Convolver Using Parabolic Horn Waveguide (포물선형 혼 도파관을 이용한 탄성 표면파 콘벌버 연구)

  • 박용욱;신현용;이승대;박정흠;윤석진;김현재
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.11
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    • pp.947-952
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    • 2001
  • In this paper, a wideband SAW convolver using a parabolic horn waveguide was designed and its characteristics were investigated. The convolver was made with parabolic horn waveguide at compression ratio 9:1 for reducing propagation loss and for improving convolution efficiency between two input IDTs of center frequency 193.78 ㎒. The SAW convolver utilizing acoustic nonlinearities of piezoelectric material demonstrated that it can provide large S/N ratio and can be use for programmable matched filter(PMF) in spread spectrum communication system.

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Distribution of Substance P Immunoreactive Neurons and Their Synaptic Organization in the Cat Thoracic Cord (고양이 흉수에서 Substance P 면역반응 신경원의 분포와 연접연구)

  • Lee, Seung-Kyun;Park, Soo-Seog
    • The Korean Journal of Pain
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    • v.9 no.2
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    • pp.326-335
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    • 1996
  • Background: Though a number of studies have described the distribution of substance P(SP)-like immunoreactivity in the spinal cord, they have been focused on lamina I and II of the dorsal horn and there are little morphological studies on the topographic distribution and ultrastructure of the SP immunoreactive neurons especially in the ventral horn of the spinal cord. this study was conducted to identify distribution pattern of SP immunoreactive neurons and to difine the synaptic organization of their processes in ventral horn of the thoracic cord of the cat by preembbeding immunocytochemical method using SP antiserum. Methods: Five adults cats of either sex were used and deeply anesthetized by intramuscular injection of ketamine. After removal of the spinal cord, samples of thoracic cord were taken and placed in fresh fixative at $4^{\circ}C$ for 2 hours. Transverse sections $50{\mu}m$ thick were processed using the preembbeding immunocytochemical method and incubated consecutively in the specific primary antibody and the 10% normal goat serum, the rabbit anti-substance P antiserum, the biotin-labelled goat anti-rabbit IgG and finally the avidin-biotin-peroxidase complex. The processed tissue sections were throughly washed and stained in the black with 1% uranyl acetate. Section were examined on a electron microscope. Results: 1) SP immunoreactive neurons were observed in the gray matter around central canal. 2) In lamina I and II SP immunoreactivity was observed in both myelinated and unmyelinated nerve fibers, but in ventral horn only in the unmyelinated nerve fibers. 3) SP immunoreactive axon terminals with small round and large dense core vesicles made chemical synapses onto the dendrites of motor neurons in the ventral horn. Conclusion: SP immunoreactive neurons might play an important role in modulation of motor neurons in the ventral horn of the thoracic cord of the cat.

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Morphine-induced Modulation of Nociceptive Spinal Dorsal Horn Neuronal Activities after Formalin-induced Inflammatory Pain

  • Park, Joo-Min;Li, Kang-Wu;Jung, Sung-Jin;Kim, Jun;Kim, Sang-Jeong
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.2
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    • pp.77-86
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    • 2005
  • In this study, we examined the morphine-induced modulation of the nociceptive spinal dorsal horn neuronal activities before and after formalin-induced inflammatory pain. Intradermal injection of formalin induced time-dependent changes in the spontaneous activity of nociceptive dorsal horn neurons. In naive cats before the injection of formalin, iontophoretically applied morphine attenuated the naturally and electrically evoked neuronal responses of dorsal horn neurons. However, neuronal responses after the formalin-induced inflammation were significantly increased by morphine. Bicuculline, $GABA_A$ antagonist, increased the naturally and electrically evoked neuronal responses of dorsal horn neurons. This increase in neuronal responses due to bicuculline after the formalin-induced inflammation was larger than that in the naive state, suggesting that basal $GABA_A$ tone increased after the formalin injection. Muscimol, $GABA_A$ agonist, reduced the neuronal responses before the treatment with formalin, but not after formalin treatment, again indicating an increase in the GABAergic basal tone after the formalin injection which saturated the neuronal responses to GABA agonist. Morphine-induced increase in the spinal nociceptive responses after formalin treatment was inhibited by co-application of muscimol. These data suggest that formalin-induced inflammation increases $GABA_A$ basal tone and the inhibition of this augmented $GABA_A$ basal tone by morphine results in a paradoxical morphineinduced increase in the spinal nociceptive neuronal responses after the formalin-induced inflammation.

Effects of GaAsAl laser on the spinal neuronal activity induced by noxious mechanical stimulation (GaAsAl 레이저가 물리적 통증반응과 관련된 척수내 신경세포의 활성에 미치는 영향)

  • Song, Young-Wha;Lee, Young-Gu;Lim, Jong-Soo
    • Journal of Korean Physical Therapy Science
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    • v.7 no.2
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    • pp.545-558
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    • 2000
  • The present study was designed to investigate the effect of low power GaAsAl laser on Fos expression in the spinal cord induced by noxious mechanical stimulation. Noxious mechanical stimulation was applied to the right hind paw following 30min of low power laser treatment using different intensity and treatment point and the resulting Fos expression in the spinal cord dorsal horn was compared to that obtained in rats exposed only to the noxious mechanical stimulation. The results were summarized as follows: 1. In intact control rats, only a few Fos like immunoreactive(Fos-IR) neurons were evident in the lumbar spinal cord dorsal horn. Similarly, following prolonged inhalation anesthesia, Fos-IR neurons were absent in the dorsal horn of the lumbar spinal cord. In animals treated with noxious mechanical stimulation, neurons with nuclei exhibiting Fos immunostaining were distributied mainly in the medial half of ipsilateral laminae I-V at lumbar segments L3-5. These findings directly indicated that prolonged anesthesia used in this study did not affect the Fos expression in the spinal cord dorsal horn of intact animals and noxious mechanical stimulation treated animals. 2. In acupoint treated animals, 10mW of laser stimulation, not 3mW intensity, significantly reduced the number of Fos immunoreactive neurons in the spinal dorsal horn induced by noxious mechanical stimulation(P<.01). However, the supressive effect of low power laser stimulatin was not observed in 3m Wand 10m W of laser stimulation into non-acupoint. These data indicate that 10mW of low power laser stimulation into acupoint is capable of inhibiting the expression of Fos in the dorsal horn induced by noxious mechanical stimulation. In conclusion, these findings raise the possibility that low power laser stimulation into acupoint may be a promising alternative medicine therapy for the mechanical stimulation induced pain in the clinical field.

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Design of Ka-band Feed Horn and Cassegrain Antenna (Ka-band 대역의 급전 혼과 카셋그레인 안테나 개발)

  • Ahn, Seung-Beom;Choo, Ho-Sung;Kang, Jin-Seob
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.8
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    • pp.943-953
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    • 2007
  • In this paper, we propose a Cassegrain antenna with a scalar feed horn opt rating in Ka-band. For an effective EM simulation of the Cassegrain antenna, the near-field of the feed hone is used ai the equivalent source of the Cassegrain antenna using the surface equivalent theorem. A corrugated circular horn operating with $HE_{11}$ mode is used as the feed horn. The angle and feed center of the main and sub reflectors are optimized to achieve maximum antenna efficiency. The designed feed horn shows the gain of 19dBi, the side-lobe level of less than -25dB and the half power beam width of $20^{\circ}$ at 33 GHz. The Cassegrain antenna shows the gain of 41dBi, the efficiency of 60%, the side-lobe level of less than -20dB and the half power beam width of $1.2^{\circ}$.

Effects of Electroacupuncture on the Expression of Cyclooxygenase in the Spinal Cord of Carrageenan-injected Rat (전침이 carrageenan유발 동통모델의 척수배각내 cyclooxygenase 발현에 미치는 영향)

  • Choi, Yung-Hyun;Lee, Yong-Tae;Choi, Byung-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.3
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    • pp.749-752
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    • 2005
  • We investigated the effects of electroacupuncture (EA) on the expression of cyclooxygenase in the spinal cord of acute inflammatory pain model. Inflammation was induced by an intraplantar injection of 1% carrageenan into the right hind paw of Sprague-Dawley. Bilateral 2 Hz EA stimulation with 0.5 mA, 1 mA and 3 mA were delivered at those acupoints corresponding to Zusanli and Sanyinjiao in man via the needles in carrageenan-injected rats. Three hours after carrageenan injection, effects of EA on cyclooxygenase (COX) expression were observed in the dorsal horn of the spinal cord using immunohistochemical method. The immunoreaction of COX-1 tended to increase in the superficial laminae and the neck of the dorsal horn as compared with normal. The COX-2 immunoreaction in the carrageenan-injected rat was also significantly increased in the all regions of the dorsal horn as compared with normal one. However, COX-1 immunoreaction in carrageenan-injected rat were decreased in the superficial laminae and neck of the dorsal horn by low intensity of EA stimulation. Except high intensity of EA stimulation in the superficial laminae, COX-2 expression was attenuated in all regions of the dorsal horn by all types of EA treatment. It is concluded that EA treatment may attenuate inflammatory pain in carrageenan-injected rat through modulating expression of COX-2 in the dorsal horn of the spinal cord.

Uterine Torsion Associated with Hydrometra and Pyometra in a Domestic Rabbit (애완 토끼에서 자궁수종, 자궁축농증, 자궁염전의 병발 증례)

  • Na, Sanggi;Choi, Jihye
    • Journal of Veterinary Clinics
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    • v.31 no.6
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    • pp.544-546
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    • 2014
  • A 1.5-year-old, female domestic rabbit was diagnosed with uterine torsion accompanying hydrometra of the right uterine horn and pyometra of the left horn. The exploratory laparotomy revealed the torsion of bilateral uterine horns in the region of the uterine cervix. No growth was detected in fluid collected from the right horn of the uterus; however, Gram-positive micrococcus and bacilli were cultured from the left horn. The pathophysiology of the simultaneous occurrence of these disorders was suspected considering that abdominal distension progressed over 4 months and the rabbit's condition deteriorated abruptly within 2 days, hydrometra was the initial disease and then infection to the left uterine horn and torsion developed later due to the large volume of fluid within the uterus. This report is the first case showing uterine torsion accompanying hydrometra and pyometra in each uterine horn.