Cardiovascular Neurons Mediating Somatosympathetic Reflex in Rostral Ventrolateral Medulla

Goo,Yong-Sook,Kim,Sang-Jeong,Kim,Jun,Sung,Ho-Kyung 대한생리학회 1993 대한생리학회지 Vol.27 No.2

The rostral ventrolateral medulla (RVLM) includes vasopressor neurons, which transmit activation signals to the intermediolateral nucleus (IML) of the spinal cord, where the preganglionic sympathetic nucleus is located, to raise arterial blood pressure (BP). However, controversy exists as to the possible depressor area in the RVLM and the pathway involved. The present study persued evidence far the location of depressor neurons and the pathway by simultaneously observing changes in BP and the firing rate (FR) of cardiovascular neurons (CVNs) in the RVLM during the somatosympathetic reflex (SSR) elicited by peripheral nerve stimulation, since CVNs are known to contribute to the generation of the sympathetic nerve discharge. In 42 cats, anaesthetized with α-chloralose, single unit recording was performed, using carbon filament electrodes inserted into the RVLM, enabling estimation of the post R wave unit histogram (PR-UNlT) and the spike triggered average of sympathetic nerve discharge (STA-SND), allowing identification of CVNs. Antidromic stimulation of spinal T₂ segment was followed to determine whether the identified CVN projects axonal endings to the spinal cord (reticulospinal neuron). The sciatic nerve was electrically stimulated at AΔ-intensity (1 mA, 0.1 ms), 1 Hz and C-intensity (10 mA, 0.5 ms), 20 Hz to elicit the depressor, and pressor responses of the SSR, respectively. Simultaneous measurement of CVN firing rate was made. Experimental results are summarized as follows. 1) 20 out of 98 CVNs had axonal projections to the spinal cord and 17 out of 98 CVNs showed FR changes during SSR. 2) Response patterns of FR and BP during SSR were classified into 8 types. 3) These 8 different response patterns could be further classified into those from pressor and depressor neurons. These results demonstrate that some CVNs were identifiable as reticulospinal neurons responding to anti-dromic stimulation and that CVNs operating as depressor neurons as well as pressor neurons exist in the RVLM, both of which are involved with SSR mediation. Therefore, evidence was found that an independent depressor pathway might be involved in the mediation of SSR.

캡슐화된 잠열 미립자 슬러리를 열 매체로 하는 축열식 냉방시스템

최준규,이재구,양현수,주태운,김필수 한국공업화학회 2003 응용화학 Vol.7 No.1

Microcapsules containing tetradecane as the phase change material (PCM) and ashell of meolamine-formalin resin were prepared by in situ polymerization. Tooptimize the encapsulation process, experiments were performed under various reaction conditions. Microcapsules with a high uniformity could be prepared, and the ratio of breakage of the microcapsules was less than 6% over 10,000 cycles using by a circulation pump. The cooling system, which has adopted MPCM slurry as a media for transporting cold thermal energy, is designed to investigate the performance of newly developed coolant. The discharging times of cold energy in circulating 20 wt% MPCM slurry are lasted to 260 minutes as long as the sensible cooling system. According, it was demonstrated that the microcapsules prepared in the current research are suitable for potential application as hat transporting media.

인터넷 사업(B2C)의 타당성 및 웹사이트 평가기준에 관한 연구

손준상,지성구 대진대학교 2001 大眞論叢 Vol.9 No.-

Recently as internet is expanding rapidly, a lot of web site and business model(B2C, B2B, C2B, B2G, P2P, etc) exist. As interests in web site increase, we are in great need of a reliable, objective, and effective model for evaluating internet web sites. The primary purpose of this study is to develop evaluation criterias for validity of Internet business(B2C) & web sites. This study will give important implications for practitioners. Our study clarifies the criteria for validity of Internet business(B2C) & web sites. The implication of this study will particularly be valuable for practitioners and entrepreneurs, future research work.

Halothane 및 Enflurane 麻醉가 肝病變에 미치는 影響에 關한 實驗的 硏究

姜俊求,姜大榮 충남대학교 의과대학 지역사회의학연구소 1988 충남의대잡지 Vol.15 No.1

In an attempt to elucidate the pathological and biochemical effects of phenobarbital and cimetidine on halothane and enflurane induced hepatic lesions, the present study in male SpragueDawley rats was undertaken to evaluate the relation betwen serum glutamic pyruvic transaminase (SGPT) and pathologic change of the liver at 0, 2, 6, 12, and 24 hours after halothane and enflurane anesthesia for 3 hours with pretreatment of phenobarbital and cimetidine. Groups of male rats received phenobarbitaal, 100mg/kg intraperitoneally, for 5 days and on the sixth day received either cimetidine, 180mg/kg intraperitoneally, or saline 60min before anesthesia. The rats received further closes of cimetidine (180mg/kg intraperitonally) or saline 1 hour and 5 hour, after anesthesia. The results were as follows 1. In the phenobarbital pretreated halothane anesthesia groups, the necrotic change of liver was mildly observed immediately after anesthesia, becoming gradually more severe, while that of enflurane anesthesia was moderately necrotic immediately after anesthesia, and after that becoming more severe. 2. In the phe:aobarbital and cimetidine pretreated halothane or enflurane anesthesia groups, the degree of the necrotic change of the liver was decreased, compared to that of phenobarbital pretreated halothane or enflurane anesthesia. 3. In the cimetidine pretreated halothane anesthesia group, the degree of the necrotic change of the liver cells was decreased, compared to that of non-cimetidine pretreated group. 4. In the phenobarbital pretreated groups, the fatty change of the liver after halothane anesthesia was similar to that of enflurane anesthesia, but in the non-phenobarbitall pretreated groups, the fatty change in ithe enflurane anesthesia group was more severe than that of halothane anesthesia. 5. In the phenobarbital pretreated group, the halothane anesthesia group followed a time course of SGPT elevation, but the SGPT value in the enflurane anesthesia group increased immediately after anesthesia and remained elevated approximately 24 hours after anesthesia. In the phenobarbital and cimetidine pretreated group, the SGPT values after halothane or enflurane anesthesia were decreased, compared to those of the non-cimetidine pretreated groups, but the decrease in SGPT concentration was significant. In summary, the results obtained by the present study indicate the pathological effects of pretreated cimetidine and phenobarbital upon acute hepatic lesions after halothane anesthesia were similar to that of enflurane anesthesia, but we supposed that the necrotic change due to enflurane anesthesia was increased by phenobarbital but relatively decreased by cimetidine.

Phenobarbital 前處置가 Halothane 麻醉時 肝病變에 미치는 影響에 關한 病理組織學的 硏究

姜俊求,姜大榮 충남대학교 의과대학 지역사회의학연구소 1984 충남의대잡지 Vol.11 No.2

Since halothane, as a new potent, nonexplosive, volatile agent, was introduced in 1956, many case reports of liver necrosis following halothane anesthesia have raised to possibility that the agent may damage the liver under certain circumstances. This study was carried out to investigate the histopathological effects of phenobarbital pretreated halothane anesthesia to the rat liver cells. Sprague-Dawley rats (male and female) were pretreated with phenobarbital; PBT(100 mg/kg/ day) for 3 days. All animals in each experimental group (saline-control, saline-anesthetized, PBT-control, and PBT-anesthetized) were fasted for 15 to 16 hours prior to each anesthesia period. PBT and Saline-pretreated animals were anesthetized together for 3 hours one to two times at 3 day intervals in a single chamber from a calibrated vaporizer. Stage III anesthesia was introduced with 1% halothane in oxygen and maintained with 0.8% to 1% halothane. Controls received the equivalent amount of saline solution. Each animal was sacrificed immediately, at 6, 12, 18, 24 and 48 hours after anesthesia respectively. The histopathological changes in the liver of the control and experimental groups were noted as follows; 1. Vacuolar degeneration of the hepatic cells of PBT pretreated rats showed more marked degree than the control. In repeated exposure of animals to the anesthetic at 3 day intervals aggravates the lesioned in control and PBT pretreated rats. 2. In first exposure to the anesthetic, fatty changes of the hepatic cells in PBT pretrea rats showed more marked in degree than the control. In repeated exposure of rats aggravates the lesions in control and PBT pretreated rats, and that of PBT pretreated rats was similar to the control. 3. The marked necrotic changes of hepatic cells were present in the PBT pretreated rats but those of the control were rarely observed. Repeated exposure of rats aggravate the lesion.

陣영湯加減方의 抗腫瘍效果에 關한 實驗的 硏究

丁俊宅,文九,文錫哉 대한한방종양학회 1998 대한한방종양학회지 Vol.4 No.1

科學技術의 發展에 따른 生活 및 醫療 수준의 向上에도 불구하고 産業發展에 따른 環境汚染, 스트레스 增加등 그 逆機能 때문에 發癌物質 또는 刺戟에의 露出등으로 인해서 全世界的으로 癌 으로 因한 死亡率이 增加되고 있다. 癌은 現在 人類의 健康을 위협하는 主要한 疾患의 하나로, 오늘날 우리 나라에서 疾患으로 因한 死亡原因中 首位를 차지하고 있다. 이러한 癌의 發生은 80%-90%가 環境的 因子에 起因한다고 報告되고 있는데 앞으로 環境性 發癌物質이 점차 增加됨에 따라 疾患者의 發生도 더욱 增加될 것으로 豫想된다. 癌의 西醫學的 治療는 주로 手術療法, 放射線療法, 化學療法 및 免疫療法이 活用되고 있다. 이중 手術療法과 放射線療法은 癌이 全身에 轉移, 增殖되기 전에 實施함으로써 效果를 거둘 수는 있으나, 癌이 原發病巢 以外에까지 轉移, 增殖되었을 경우에는 이 두가지 方法의 局所療法만으로서는 좋은 治療效果를 거주기 어렵다. 따라서 최근 抗癌劑에 의한 化學療法이 다른 方法보다 有效하다고 認定이 되어 가장 많이 活用되고 있으나, 癌腫에 대한 感受性差異, 治療後의 副作用, 再發 및 合倂症 등의 問題點 때문에 副作用을 減少시키면서 抗癌效果를 높이는 治療法이 계속 硏究되고 있다. 이에 1972年 美國 國立癌硏究所에서 實施한 抗癌劑 開發硏究에 있어서 抗腫瘍性 Screening test에 利用된 物質中 약 47%가 天然物質이었다는 사실은 注目할만 하다. 韓醫學的 治療法은 最近에 辨證施治를 根幹으로 하여 健脾益氣를 爲主로한 扶正祛邪法과 扶正培體法이 많이 活用되고 있으며 扶正法으로는 益氣健脾, 滋陰補血, 溫補脾?? 등이, 祛邪法으로는 活血祛療法, 淸熱解毒法, 軟堅化痰法 등이 活用되고 있는데, 이를 根據로 하여 韓藥의 複方,單味,單味抽出物 등의 投與와 鍼,灸,水鍼,電鍼, laser鍼등의 治療方法을 手術 後 或은 化學療法이나 放射線治療와 竝行하여 治療效果가 向上되었다고 報告하고 있다. 抗癌劑의 抗癌效果 程度를 檢査하는 方法은 크게 5가지로 分類되는데, 하나는 細胞를 藥劑에 露出시킨 후 顯微鏡을 통하여 나타난 形態學的 變化를 가지고 藥劑의 效果程度를 決定하는 方法이고, 둘째는 Dye exclusion assay 方法으로 살아있는 細胞가 trypan blue, eosin, nigrosin과 같은 染色液에 染色되지 않는 점을 利用한 것이며, 세 번째는 抗癌劑 대자석. 丁香, 枇杷葉, 抗癌作用을 가진 龍癸, 半技蓮, 牡蠣, 夏枯草, 猪? 等의 藥物로 구성되어 있다. 近來 單一藥物의 抗癌效果에 대한 實驗的 硏究로는 金^27,28)등에 의한 人蔘, 鹿茸 의 抗體生産 抑制 緩和效果 및 任^29)에 의한 魚腥草,鹿血, ??, 穿山甲 등이 正常 免役細胞에는 거의 毒作用을 일으키지 않으면서 强力한 抗癌效果가 있다는 報告, 金^31-34)등에 의한 紫率, 東風蔡, 靈芝, 仙鶴草, 巴豆 등이 抗癌作用 및 免疫反應에 效果를 미친다는 報告 등이 있고, 複合藥劑 藥物의 抗癌效果에 대한 硏究로는 姜^36-38)등에 息賁丸, 肥氣丸 및 비기환이 白血病과 淋巴腫患者에서 抽出한 癌細胞에 抗癌效果가 있다는 報告 및 金^37-39)등에 의한 伏梁丸, 비 氣丸 및 消積正元散이 各種 癌細胞柱의 成長沮碍 效果, 尹^30,35,40,42)등에 의한 六君子湯, 小柴胡湯, 四妙湯, 大柴胡湯, 防毒湯, 半夏白 朮天麻湯, 巴豆를 加味한 四君子湯 및 四物湯 등이 抗癌作用 및 免疫反應에 效果를 보인다는 報告등이 있었으나, 아직까지 진령탕가감방의 抗癌效果에 대한 實驗的硏究는 없었다. 이에 著者는 抗癌效果가 있을 것으로 推定되는 진령탕가감방의 抗腫瘍效果를 알아보기 위하여, 水溶性 抽出液을 얻은 후 現代 病理學的으로 多用하는 colony形成制實驗, SRB assay에 의한 抗腫癌效果, 生命延長率, 化學的인 方法과 癌腫細胞 移植에 의한 腫瘍 誘發을 통하여 癌 發生 및 그 經過에 미치는 影響 및 NK細胞活性에 미치는 影響 등을 觀察하였다. 本 實驗에서는 진령탕가함방의 腫瘍細胞에 대한 增殖抑制作用을 觀察하고자 in vitro test인 colony形成抑制實驗과 SRB assay를 利用하였는데, 진령탕가함방의 抽出液이 腫瘍細胞의 成長을 抑制하는 效果가 濃度依存的으로 增加하는 結果를 보여 抗腫瘍의 效果가 있음을 나타냈고(table3,4)in vivo assay로서 sarcoma 180 복수암세포를 移植한 마우스의 平均生存期間 및 生命延長率이 뚜렷하게 增加되었다.(table5). 또한 진령탕가함방 抽出液 마우스에 투여하면 MCA 유도한 종양 및 3LL 細胞移植에 의한 腫瘍의 發生率 및 發生된 腫瘍의 크기가 현저히 減少되었다.(table7). 이러한 效果는 진령탕가감방이 感受性 癌腫細胞에 직접적으로 影響을 미쳐 그 增殖이 抑制되었을 可能性을 생각할 수 있다. 그렇지만 本 硏究에서는 癌腫特異性에 관한 結論을 내릴 수는 없으므로 癌腫特異性 관한 硏究는 進行해야 할 것으로 생각된다. 또 다른 可能한 진영탕가함방 抽出液 抗腫瘍 作用機轉은 진영탕가함방 抽出液이 NK細胞의 活性을 亢進시킨 實驗結果로 類推하여, 진영탕가함방 抽出液이 腫瘍마우스에 非特異的인 免疫活性을 促進시킴으로써 진영탕가함방 抽出液의 抗腫瘍作俑과 발현괼 可能性도 생각할 수 있다. 따라서 앞으로 여러 癌腫細胞에 대한 진영탕가감방 抽出液의 抗 腫瘍 作用과 腫瘍動作에서의 진영탕가함방 抽出液 投與에 의한 生體生理現象의 變化, 生理活性物質의 本態 등을 밝히기 위한 보다 具體的이고 廣範圍한 硏究가 數行되어져야 되리라고 思料된다. 細胞性 免疫反應中 重要한 役割을 하는 작동세포증 NK細胞는 여러 腫瘍에 대해 自然殺害能을 보여 소위 T非依存性 免疫監視機轉에 관하여는 바이러스 및 細菌에 感染된 細胞를 破壞하는 活性을 가지며, IL-2 및Interferon 등에 의하여 活性이 增加된다. NK細胞가 표적세포를 破壞하는 機轉에 관해서는 아직 확실히 알려져 있지 않으나, 첫째로 표적세포를 認識하는 時期, 둘째로 融解機轉을 活性化시키는 時期, 세째로 NK lymphotoxin이 邊離되는 時期, 네째로 표적세포의 死成期로 나눌 수 있다. 本 實驗에서 진영탕가감방 抽出液으로 前妻理시 NK細胞의 표적세포와의 結合能은 물론 結合된 표적세포의 融海能이 促進된 結果를 보이는데(Table 8), 이와 같은 結果는 진영탕가감방 抽出液이 NK細胞의 표적세포 파괴 4단계 전체를 亢進시킨 結果로 認定된다. 이상에서 다음과 같은 결론을 얻었다. 1. 진영탕가감방 抽出液을 폐암세포주인 A549와 간암세포주인 hep3B 및 신장암 유래의 종양세포주인 Caki-l cell에 投與한 결과, in vitro test인 coloy形成抑制實驗과 SRB assay에서 모두 濃度依存的으로 암세포주 成長을 抑制하였다. 2. Sarcoma 180細胞를 마우스에 移植하여 平均生存期間 및 生命延長率을 測定하는 in vivo test에서는 진영탕가감방 抽出液이 마우스의 平均生存期間 및 生命延長率을 增加시키는 結果를 보였다. 3. 진영탕가감방 抽出液은 MCA로 誘導한 腫瘍의 發生率 및 發生腫瘍의 크기를 현저히 減少시켰으며. 3LL細胞 移植에 의한 腫瘍發生 또한 현저히 減少시켰다. 4. 진영탕가감방 抽出液은 NK細胞의 活性度를 增加시켰다. 특히 10ug/ml농도 에서 NK細胞 活性度가 가장 현저히 增加되었다. 以上의 結果로 보아 진영탕가감방은 癌腫細胞에 대한 直接的인 成長抑制 및 細胞의 活性을 통한 免疫增進에 의해 多樣한 抗腫瘍效果를 보인 것으로 思料된다. The sprig of Jinryungtang Gagambang(陳영湯加減方) has been used for curing as a traditional medicine without any experimental evidence to support the rational basis for their clinical use. This experiment was carried out evaluate the possible therapeutic or antitumoral effect of Jinryungtang Gagambang extract against vancer, and to study some mechanisms responsible for its effect. The cytotoxic and antitumor effects were evaluated on human cell lines(A549, hep3B, Caki-1,Sarcoma 180 after exposure to Jinryungtang Gagambang extract using in ILS. colony forming efficiency and SRB assay which were regarded as a valuable method for cytotoxic and antitumor effects of unknown compound on tumor cell lines. The results obtained in this were as folows. 1. As a result of exposure to Jinryungtang Gagambang extract, the proliferation of A549, hep3B, Caki-1, good correlation were shown from the results of SRB assay and those of clogenetic assay. 2. The administration of Jinryungtang Gagambang extract showed significant effects of increase of MST(mean survival time) and ILS(increased lufe span) depending on the increasing concentration. 3. Against squamous cell carcinoma induced by MCA, Jinryungtang Gagambang decreased not only the frequency of tumor production but also the number and weight of tumors per tumor bearing mice(TBM). Jinryungtang Gagambang also significantly supressed the development of 3LL cell-implanted tumors by frequency and their size, and some developed tumors were regressed by the continuous treatment of Jinryungtang Gagambang extract into TBM. 4. Jinryungtang Gagambang extract also increased NK cell activities. According to the above results, it could be suggested that Jinryungtang Gagambang extract has prominent antitumor effect.

DGS 구조를 이용한 DPDT 스위치의 설계 및 제작

조홍구,박준석,안가람 국민대학교 생산기술연구소 2004 공학기술논문집 Vol.27 No.-

In this paper a DPDT(Double-Pole Double Through) switch with defected ground structure(DGS) is proposed. The equivalent circuit for the proposed switch structure is derived according to based on equivalent circuit of proposed DGS unit structure. The equivalent circuit parameters of DGS unit are extracted by using the circuit analysis method. The on/off operation of the proposed switch is obtained by varying the capacitance of the varactor diode at the defected ground plane. In the case of ON state, the insertion loss of the fabricated DPDT was shown under 1dB. And in OFF state, we found the rejection characteristic over 20dB at the designed frequency 2.45GHz. The experimental results show excellent insertion loss at on state and isolation at off state.

연산 증폭기 (TL494) 를 이용한 DC/DC 승압 컨버터 제어 시스템 설계

정구종,이혜연,문경주,정유석,이준영,손영익 明知大學校 産業技術硏究所 2009 産業技術硏究所論文集 Vol.28 No.-

A simple control system using an op Amp (TL494) is presented for a DC/DC boost converter. The DC/DC boost converters have many industrial applications including renewable energy sources and hybrid automobiles. The problem of regulating the output voltage in the presence of load variation has been a research subject of interest for many years. After computer simulations with SimPower system of Matlab Simulink, we have developed the converter system in university laboratory according to the design specifications. Since the chip TL494 has both op Amp and PWM comparator even beginners can easily develop the control system. Experimental results show that the proposed system has some robustness with respect to the load variation.

이동 통신 환경에서 혼합형 방식의 효율적인 위치 관리 기법

박태준,이구연 강원대학교 정보통신연구소 2005 정보통신논문지 Vol.9 No.-

In this paper, we proposed a new hybrid location management scheme which combines the movement-based and the time-based location updating policy. In the Hybrid scheme, the location of a mobile subscriber is updated after there are d cell boundary crossing and the timer expires. Simulation results of the hybrid location management scheme show the good performance when the mobile communication system's environment has low CMR (Call to Mobility Rate) and high updating cost. In addition, the hybrid location management scheme is robust in a variety of mobile terminal's mobility.

卵巢 畸形腫의 病理組織學的 硏究

姜大榮,姜俊求 충남대학교 의과대학 지역사회의학연구소 1984 충남의대잡지 Vol.11 No.2

For study on cystic teratoma of ovary, the operation specimens were collected at the depatment of pathology, Chungnam National University College of Medicine from July 1975 to June 1984 and analyzed its histopathologic characteristics and clinical features. The results were as follows; 1. The total number of cystic teratorna were 220 cases, which were 105 cases (47. 7%) in the right ovary, 93 cases (42.3%) in the left ovary, and 22 cases (10%) in both ovaries. They occurred almost equally on either side. 2. The age distribution was highest in the third decade, 91 cases (41%). Ninety percent occurred during the reproductive years. 3. The average diameter was 8.7cm. 4. Microscopically ectodermal derivatives were most frequently present, followed by mesodermal structures and endodermal derivatives. 5. Most common complaint was palpable mass (37%), followed by pain. Most frequent complication was torsion, in which 23 cases (10%) were included. Malignant transformation was found in 2 cases (about 1%).