• International Journal of Naval Architecture and Ocean Engineering
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• 제9권2호
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• pp.127-134
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• 2017

Vortex Induced Vibration (VIV) is a typical flow-structure interference phenomenon which causes an unsteady flow pattern due to vortex shedding at or near the structure's natural frequency leading to resonant vibrations. VIV may cause premature fatigue failure of marine risers and pipelines. A test model was carried out to investigate the role of a stationary fairing by varying the caudal horn angle to suppress riser VIV taking into account the effect of wake interference. The test results show significant reduction of VIV for risers disposed in tandem and side-by-side. In general, fairing with a caudal horn of $45^{\circ}$ and $60^{\circ}$ are efficient in quelling VIV in risers. The results also reveal fairing can reduce the drag load of risers arranged side-by-side. For the tandem configuration, a fairing can reduce the drag load of an upstream riser, but will enlarge the drag force of the downstream riser.

• Biomolecules & Therapeutics
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• 제1권1호
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• pp.37-43
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• 1993

Electrical or chemical stimulation of many areas in the brainstem modulates activity of dorsal horn neurons (DHN). This is known to be mediated by a population of bulbospinal neurons. Yet, little is known about responses of DHNs to stimulation of the caudal ventrolateral medulla (CVLM). Thus, the purpose of the present study is to see if there is any change in activity of DHNs when CVLM is stimulated electrically. Thirty-one DHNs were recorded from dorsal horn of the spinal cord. Fourteen DHNs (45%) were classified as wide dynamic range neurons and 9 (19%) were high threshold cells, and 4 (13%) and 4 (13%) were deep and low threshold neurons, respectively. Among 31 neurons tested for responses to stimulation of CVLM, 21 DHNs (68%) were inhibited by the electrical stimulation of CVLM ($200{\mu}A,\;100{\mu}s$ duration, 100 Hz), and 9 cells (39%) did not show any change in neuronal activity. One neuron was excited by the stimulation. The electrical stimulation of CVLM not only inhibited spontaneous activity of DHNs but also inhibited evoked responses of DHNs to somatic stimulation in the receptive field. These data suggest that CVLM is one of the pain-modulatory areas that control transmission of ascending information of noxious input to the brain from the spinal cord.

• The Korean Journal of Physiology
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• 제25권2호
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• pp.211-221
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• 1991

Although the existence of nerve cells which determine the activity of sympathetic nervous system in ventrolateral medulla is advocated recently, there are wide varieties on the location and function of them according to authors. Present study aimed to identify and characterize the medullospinal tract cells in rostral and caudal medulla of cats .which branch to the lateral horn of the upper thoracic spinal cord. Cats were anesthetized with ${\alpha}-chloralose$. The upper thoracic spinal cord and floor of the IVth ventricle were exposed. Medullospinal tract cells in rostral and caudal medulla were identified by anti-dromic stimulation of the intermediolateral nucleus in the upper thoracic cord and then the location and physiological characteristics of these cells were studied. A total of seventy cells in medulla had constant latency and responded to high frequency stimulation to thoracic cord. Among them fifty-six cells were identified as medullospinal tract cells either by collision with spontaneous activities or activities evoked by sciatic nerve stimulation(27/56), or by determining the refractory period (29/56). Thirty-one of these cells branched to the contralateral thoracic spinal cord, twenty-one cells to the ipsilateral side and remaining four cells branched to both sides. The conduction velocity of cells branching to the contralateral side was $29{\pm}2.9\;m/sec$ and that of cells to the ipsilateral side was $39.1{\pm}6.0\;m/sec$. When medulla was devided into two by a horizontal plane at 3 mm rostral to the obex, fifty-one among seventy cells were in the rostral medulla and nineteen were in the caudal medulla. The conduction velocities of these two groups were $21.6{\pm}1.0\;and\;33.3{\pm}3.9\;m/sec$, respectively. In this study, we confirmed the existence of two groups of medullospinal tract cells in rostral and caudal ventrolateral medulla, which branch to the lateral horn of thoracic cord and these cells have relatively few spontaneous activities and rapid conduction velocity, so we concluded that these cells are different from the previously known sympatho-related cells in ventrolateral medulla.

• The Korean Journal of Pain
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• 제1권1호
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• pp.74-79
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• 1988

Caudal narcotic analgesia was assesses after the injection of 3mg morphine diluted in 30ml (physiologic) saline into the sacral canal in 15 Patients after upper abdominal surgery, in 20 patients after lower abdominal surgery under general anesthesia, and in 20 patients after perianal surgery under caudal block. Pain relief was evaluated by the subsequent need for systemic analgesics. All eases had considerable relief from pain an4 the morphine was effective for 12 or more hours. There were no significant differances between pain relief of the upper abdominal and lower abdominal surgery group, upper abdominal and perianal surgery group, and lower abdominal and perianal surgery group (p>0.05, p>0.05, p>0.05). It is suggested that the morphine, which was administered into the sacral, cannal, reached the subarachnoid space and produced it's effect by direct action on the specific opiate receptors in the substantia gelatinosa of th.8 posterior horn cell of the spinal cord. Consequently, whether analgesia from epidural narcotics appears to be segmental in distribution or not is still in controversy.

• Animal Systematics, Evolution and Diversity
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• 제38권4호
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• pp.167-198
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• 2022

Ten species of copepods, including nine new species, associated with compound ascidians are recorded from Korean waters. Nine new species can be characterized by their major diagnostic features, as follows: Botryllophilus pentamerus n. sp. by having a five-annulated abdomen; B. paucisetatus n. sp. by the presence of four and three setae on the exopods of right and left leg 1, respectively; Haplostoma quadridens n. sp. by the presence of four lobes on the labrum and one seta plus four spines on the exopods of legs 1-4; H. paucidens n. sp. by the presence of only two spines on the distal segment of the antenna; Enterocola horridus n. sp. by having five setae on the antenna, no seta on the caudal ramus, and two setae on leg 5; E. longicaudatus n. sp. by having long caudal rami which are more than three times as long as wide; Thoracodelphys bisetata n. sp. by the presence of only two setae on the basis of the maxillule; T. cerasta n. sp. by the presence of a large, horn-like process on the distal margin of the basis of leg 2; and Unimeria hirsuta n. sp. by having three setae on the terminal segment of the maxilla. Zygomolgus didemni (Gotto, 1956) previously known only from European waters is reported from Korean waters, with a redescription and illustrations.

• The Korean Journal of Physiology and Pharmacology
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• 제1권3호
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• pp.251-262
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• 1997

Peripheral nerve injury sometimes leads to neuropathic pain and depletion of calcitonin gene related-peptide (CGRP) and substance P (SP) in the spinal cord. However, the pathophysiological mechanisms for depletion of CGRP and SP following the neurorathic injury are still unknown. This study was performed to see whether the distribution of immunoreactivity for CGRP and SP in the superficial dorsal horn and dorsal root ganglia(DRG) was related to the distance between the DRG and injury site. To this aim, we compared two groups of rats; one group was subjected to unilateral inferior and superior caudal trunk transections at the level between the S3 and S4 spinal nerves (S34 group) and the other group at the levels between the S1 and S2, between S2 and S3 and between S3 and S4 spinal nerve (S123 group). The transections in both groups equally eliminated the inputs from the tail to the S1-3 DRG, but the distance from the S1/S2 DRG to the injury site was different between the two groups. Immunostaining with SP and CGRP antibody was done in the S1-S3 spinal cord and DRG of the two groups 1 and 12 weeks after the injury. The results obtained are as follows: 1. The immunoreactivity for CGRP and SP in the ipsilateral superficial dorsal horn and DRG decreased 1 and 12 weeks after neuropathic nerve injury. 2. The immunoreactive area of SP and CGRP in the S1 dorsal horn was smaller in the S123 group than in the S34 group, whereas that in the S3 dorsal horn was not significantly different between the two groups. The number of SP-immunoreactive DRG cells decreased on the neuropathic side as compared to the sham group's in all DRGs of experimental groups except the S1 DRG of the S34 group. These results suggest that the amounts of SP and CGRP in the dorsal horn and DRG following neuropathic injury inversely decrease according to the distance between the DRG and injury site.

• The Korean Journal of Physiology and Pharmacology
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• 제21권4호
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• pp.371-376
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• 2017

The caudal subnucleus of the spinal trigeminal nucleus (medullary dorsal horn; MDH) receives direct inputs from small diameter primary afferent fibers that predominantly transmit nociceptive information in the orofacial region. Recent studies indicate that reactive oxygen species (ROS) is involved in persistent pain, primarily through spinal mechanisms. In this study, we aimed to investigate the role of xanthine/xanthine oxidase (X/XO) system, a known generator of superoxide anion ($O_2{^-}$), on membrane excitability in the rat MDH neurons. For this, we used patch clamp recording and confocal imaging. An application of X/XO ($300{\mu}M/30mU$) induced membrane depolarization and inward currents. When slices were pretreated with ROS scavengers, such as phenyl N-tert-butylnitrone (PBN), superoxide dismutase (SOD), and catalase, X/XO-induced responses decreased. Fluorescence intensity in the DCF-DA and DHE-loaded MDH cells increased on the application of X/XO. An anion channel blocker, 4,4-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), significantly decreased X/XO-induced depolarization. X/XO elicited an inward current associated with a linear current-voltage relationship that reversed near -40 mV. X/XO-induced depolarization reduced in the presence of $La^{3+}$, a nonselective cation channel (NSCC) blocker, and by lowering the external sodium concentration, indicating that membrane depolarization and inward current are induced by influx of $Na^+$ ions. In conclusion, X/XO-induced ROS modulate the membrane excitability of MDH neurons, which was related to the activation of NSCC.

• 대한수의학회지
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• 제38권3호
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• pp.474-487
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• 1998

The present study was undertaken to investigate the morphological characteristics of trigeminal nerve in the Korean native goat by macroscopic methods. Trigeminal nerve was originated from the lateral side of pons, and extended shortly forward to form trigeminal ganglion at the opening of oval foramen. Thereafter this nerve was divided into maxillary, mandibular and ophthalmic nerve. Ophthalmic nerve gave off the zygomaticotemporal branch, frontal nerve, frontal sinus branch, and was continued as the nasociliary nerve. Maxillary nerve gave rise to the zygomaticofacial branch, accessory zygomaticofacial branch, communicating branch with oculomotor nerve, pterygopalatine nerve, caudal superior alveolar branch, malar branch and was continued as the infraorbital nerve. Mandibular nerve was divided into the masseteric nerve, buccal nerve, lateral pterygoid nerve, medial pterygoid nerve, nerve to tensor tympani m., auriculotemporal nerve, and furnished the inferior alveolar nerve and lingual nerve as terminal branches. The course and distribution of the trigeminal nerve in the Korean native goat appeared to be similar to that in other small ruminants such as sheep and goat. But the main differences from other small ruminants were as follows : 1. There was no accessory branch of the major palatine nerve. 2. The caudal superior alveolar branch was directly branched from the maxillary nerve. 3. The communicating branch with oculomotor nerve was originated from maxillary nerve or common trunk with zygomaticofacial branch. 4. The malar branch arose from the maxillary nerve at the rostral to the origin of the caudal superior alveolar branch. 5. The inferior alveolar nerve originated in a common trunk with the lingual nerve. 6. The mylohyoid nerve arose at the origin of the inferior alveolar nerve. 7. The zygomaticotemporal branch was single fascicle, and gave off lacrimal nerve and cornual branch. 8. The base of horn was provided by the cornual branches of zygomaticotemporal branch and infratrochlear nerve of nasociliary nerve.

• 대한수의학회지
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• 제36권2호
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• pp.289-296
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• 1996

A case of schistosomus reflexes in Korean native female calf was observed macroscopically and radiographically. The results were summarized as follows. 1. The abdominal visceral organs were exposed. 2. The vertebral column bent laterally to the left, and the sacrum approached to the cranium by reflected caudal lumber vertebrae, presenting S-shaped lateral twisting of the vertebrae. 3. The right ribs reflected laterally and dorso-cranially from the 7th rib to 13th rib. The left ribs bent caudally from 8th rib to 13th rib. 4. The length of rudimentary 6th right rib was one half of normal size and the 7th right rib was one third. 5. The sternum was bifid split from the fourth sternebra through the xyphoid cartilage. 6. The diaphragm was intact and thoracic cavity was reduced in size. The lung and heart severely deformed in shape and size. 7. The liver markedly deformed in shape and thickness. 8. The pelvic cavity was reduced in size by compression laterally to the left. 9. The uterus horn, ovary, urinary bladder, and urethra were severely deformed in the shape and position.

• 한국수정란이식학회지
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• 제18권2호
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• pp.97-108
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• 2003

체외수정된 한우 수정란을 PCR 기법에 의한 성감별을 위해 생검하여 회복시까지 1∼2시간 동안 배양하였다. 이 성감별된 한우 수정란을 2000년 2월부터 2001년 2월까지 한우 49두와 젖소 16두에 이식하였다. 수정란이 이식된 65두의 수란우중 14두(한두 12두, 젖소 2두)가 성감별 결과와 동일한 성의 산자를 생산하였고, 전체 수태율은 21.5%를 나타내었다. 1. 총 65두의 수란우중 웅성 수정란은 35두에 자성 수정란은 30두에 이식되었고 이중 분만된 산자 14두중 웅성은 6두, 자성은 8두였으며 PCR에 의한 성감별 정확도는 100.0%를 나타내었다. 2. 성감별된 한우 수정란은 한우와 젖소에 이식한 후 수태율은 각각 24.5, 12.5%를 나타내었다. 3. 성감별된 한우의 신선수정란과 동결-융해된 수정란의 이식후 수태율은 각각 23.5, 14.3%를 나타내었다. 4. 성감별된 한우 수정란의 이식 시기에 따른 수태율은 봄, 여름, 가을, 겨울에 각각 11.8, 29.4, 23.4, 20.0%를 나타내었다 5. 성감별된 한우 수정란의 상태에 따른 이식후 수태율은 excellent, good, fair군에서 각각 41.7, 30.0, 0.0%를 나타내었다. 6. 성감별된 한우 수정란의 이식시 수란우의 자궁각 두께에 따른 이식후 수태율은 0, +, ++, +++군에서 각각 71.4, 18.9, 11.8, 0.0%를 나타내었다. 7. 성감별된 한우 수정란이 주입된 수란우 자궁각 부위에 따른 이식후 수태율은 자궁각 선단부, 중심부, 미부에서 각각 30.0, 20.0, 10.0%를 나타내었다. 8. 성감별된 한우 수정란의 이식시 수란우의 황체의 상태에 따른 이식후 수태율은 excellent, good, poor군에서 각각 41.2, 14.3, 15.4%를 나타내었다. 9. 성감별된 한우 수정란을 straw에 장착후 이식시까지 10, 15, 20, 25, 30분 경과에 따른 이식후 수태율은 18.2, 30.0, 30.0, 0.0, 25.0%를 나타내었다. 10. 성감별된 한우 수정란의 이식시 수란우의 산차에 따른 이식후 수태율은 1산차, 2산차, 3산차, 4산차에서 각각 26.5, 19.1, 14.3, 0.0%를 나타내었다. 이상의 결과에서 성감별된 수정란의 이식시 양호한 수태율을 얻기 위해서는, 신선수정란이 동결수정란 보다 유리하다는 점과 생검후 수정란의 회복상태, 수란우의 자궁각 두께, 수정란의 수란우 자궁각 주입부위, 수란우의 황체 상태, 이식시까지 소요시간, 수란우의 산차를 고려해야 한다는 것을 알 수 있었다.