• Title/Summary/Keyword: rCBF

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Reliable Contention-Based Forwarding Approach (Contention-Based Forwarding의 신뢰성 향상 방안)

  • Sung, Yoon-Young;Jo, Sun-Mi;Lee, Mee-Jeong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.8B
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    • pp.695-705
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    • 2012
  • Due to recent advances in wireless devices and the automotive industry, Vehicular Ad hoc Networks (VANETs) have emerged as a very promising technology for transferring data collected on the road by moving cars. The delivered data may contain emergency information which affects the safety of passengers and drivers as well as the traffic congestion, and the routing protocols have thus a significant impact on the performance of VANETs. In this paper, we study the impact of movement direction of the participating cars which forward data packets on the performance of data delivery and present a new approach which extends the contention-based forwarding (CBF). The proposed reliable CBF (R-CBF) increases the reliability of data deliver on the traffic lights installed roads and reduces the overall propagation delay without routing loops or interruption of data forwarding that may be caused by changes of relative positions of involving cars in routing. Simulation demonstrates that the R-CBF diminishes propagation delay by 38% in comparison to G-SRMB which forwards data to moving cars in the backward direction and eliminates unnecessary retransmissions.

Effects of Mixture of Yukgunja-tang and Bambusae Caulis in Liquamen on the Regional Cerebral Blood Flow and Mean Arterial Blood Pressure in Rats (육군자탕(六君子湯)과 죽력(竹瀝) 혼합물이 국소 뇌혈류량 및 평균혈압에 미치는 효과)

  • Lee, Seok-Jin;Jeong, Hyun-Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.1
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    • pp.54-61
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    • 2007
  • The study was designed to investigate the effects of Mixture of Yukgunja-tang and Bambusae Caulis in Liquamen (YTBCL) on the change of regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in rats, and further to determine the mechanism of action of YTBCL. The results in rats were as follows ; YTBCL 25 ${\mu}l$ significantly decreased rCBF and MABP compared with basal condition. YTBCL 100 ${\mu}l$ significantly increased rCBF compared with basal condition, but decreased MABP compared with basal condition. YTBCL 50 ${\mu}l$ significantly increased rCBF compared with basal condition, but MABP was somewhat decreased compared with basal condition. The VTBCL 50 ${\mu}l$-induced increase in rCBF was significantly inhibited by pretreatment with methylene blue (10 ${\mu}g$/kg, i.p.), an inhibitor of guanylate cyclase and indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase. The YTBCL 50 ${\mu}l$-induced decreased MABP significantly increased by pretreatment with methylene blue but was inhibited by indomethacin. This results were suggested that the mechanism of YTBCL was mediated Dy guanylate cyclase.

Effects of Flos Sophora japonica Extract on the Changes of Cerebral Hemodynamics

  • Rha, Young-Ah;Lee, Woo-Sik;Park, Sung-Jin
    • Culinary science and hospitality research
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    • v.20 no.5
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    • pp.67-70
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    • 2014
  • The purpose of this study was to measure the changes of regional cerebral blood flow(rCBF) and blood pressure(BP) in rats, following the intravenous injection of Flos Sophora japonica L.(FSJ) water extract. The measurement was continually monitored by Laser-Doppler Flowmeter and pressure transducer in anaesthetized adult Sprague-Dawley rats for 2 hours to 2 hours and a half through the data acquisition system. FSJ increased the changes of rCBF in rat significantly. The rCBF of FSJ did not change by pretreated propranolol, atropine, L-NNA($N^G$-nitro-L-argininine) and indomethacin. But the rCBF of Flos Sophora japonica L. was increased by pretreated methylene blue. FSJ decreased the changes of BP, significantly. The BP of FSJ did not change by pretreated propranolol, atropine, L-NNA and indomethacin. But the BP FSJ was decreased by pretreated methylene blue. There results indicated that FSJ can increase the rCBF and decrease the BP, that is related to guanylyl cyclase activity.

Effects of Palmul-Tang on the Change of Cerebral Hemodynamics in Rats (팔물탕이 뇌혈류역학 변화에 미치는 효과)

  • Park Cheol Hun;Bae In Tae;Jeong Hyun Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.18 no.4
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    • pp.1014-1020
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    • 2004
  • The study was designed to investigate the effects of Palmul-Tang(PMT) on the change of cerebral hemodynamics [regional cerebral blood flow(rCBF), pial arterial diameter(PAD) and mean arterial blood pressure(MABP)] in normal and cerebral ischemic rats. The change of rCBF and MABP were determinated by laser-doppler flowmetry(LDF), and the change of PAD was determinated by video-microscopy. The results in normal rats were as follows ; PMT significantly increased rCBF and PAD in a dose-dependent, and PMT increased MABP in a dose-dependent. This results were suggested that PMT significantly increased rCBF by dilating PAD. The results in cerebral ischemic rats were as follows ; Both rCBF and PAD were significantly and stably increased by PMT(10㎎/㎏, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. The present authors thought that PMT had an anti-ischemic effect through the improvement of cerebral hemodynamics.

Effects of Sambutang and Consitituent Herbs on the Regional Cerebral Blood Flow and Mean Arterial Blood Pressure in Rats (삼부탕(蔘附湯) 및 구성약물(構成藥物)이 백서(白鼠)의 국소뇌혈류량(局所腦血流量)과 혈압(血壓)에 미치는 영향(影響))

  • Hong Seok;Kang Hwa-Jung;Kim Kyung-Seon;Kim Kyung-Su;Jeon Hong-Yeol
    • Herbal Formula Science
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    • v.10 no.1
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    • pp.93-103
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    • 2002
  • This experimental studies were done to investigate the effects of Sambutang(SBT) and consitituent herbs on the regional cerebral blood flow(rCBF) and mean arterial blood pressure(BP) in rats. The results are as follows: SBT and consitituent herbs(SBT omitting Zingiberis Rhizoma Recens, Zingiberis Rhizoma Recens. Ginseng Radix and Aconiti iateralis preparata Radix) was increased rCBF significantly in a dose-dependent manner. SBT omitting Zingiberis Rhizoma Recens and Ginseng Radix were decreased significantly BP in rats. But, SBT, Aconiti iateralis preparata Radix and Zingiberis Rhizoma Recens were not affected BP in rats. According to the above findings. it is suggested that SBT causes a diverse response of rCBF, and specially the rCBF by increasing SBT is mediated action of Zingiberis Rhizoma Recens.

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Experimental Study of Samul-tang Extract and Bambusae caulis in liquamen on the Regional Cerebral Blood Flow and Mean Arterial Blood Pressure in Normal Rats (사물탕합죽력(四物湯合竹瀝)이 국소 뇌혈류량과 평균 혈압에 미치는 실험적 연구)

  • Cho, Young-Lim;Jeong, Hyun-Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.6
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    • pp.1394-1400
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    • 2007
  • This study was designed to investigate the effects of Samul-tang Extract and Bambusae caulis in liquamen(SEB) on the changes in regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in normal rats. The results were as follows ; SBE significantly increased rCBF in a dose-dependent manner, and increased MABP in a dose-dependent manner. This result suggests that SBE significantly increased rCBF by dilating pial arterial diameter. Increase of SBE-induced rCBF was significantly inhibited by pretreatment with indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase and increase of SBE-induced rCBF was inhibited by pretreatment with methylene blue ($10\;{\mu}g/kg$, i.p.), an inhibitor of guanylate cyclase. Increase of SBE-induced MABP was significantly increased by pretreatment with methylene blue but increase of SBE-induced MABP was decreased by pretreatment with indomethacin. These results suggested that the action of SBE was mediated by cyclooxygenase.

The Effects of Samsoeum Extracts on Regional Cerebral Blood Flow and Blood Pressure in Mice (삼소음(蔘蘇飮)이 백서(白鼠)의 국소뇌혈류량(局所腦血流量)과 혈압(血壓)에 미치는 영향(影響))

  • Park, Byong-Min;Hong, Jae-Eui;Ko, Young-Chul;Shin, Jo-Young;Lee, Si-Hyeong
    • The Journal of Internal Korean Medicine
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    • v.23 no.1
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    • pp.33-39
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    • 2002
  • Objective : The objective of this study is to measure the changes of regional cerebral blood flow(rCBF) and blood pressure(BP) in rats with the following injection. Methods : The measurement was continually monitored by laser-doppler flowmeter-Transonic Instrument, USA- and pressure tranducer(Grass, USA) in anesthetized adult Sprague-Dawley rats about for two hour to two hour and a half hours through the data acquisition system composed of Maclab and Macintosh computer. Result : This experiment with Samso-eum increased the changes of rCBF in rats, significantly, but did not change the blood pressure. The rCBF of Samso-eum decreased by pretreated propranolol, and was not changed by pretreated L-NNA and ODQ. Conclusion : It is considered that the dosage-dependent increase on rCBF is mediated by adrenegic ${\beta}$-receptor.

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Effects of Acanthopanax Sessiliflorus $S_{EEM}$ Ethyl Alcohol Extract on the Cerebral Blood Flow and Mean Arterial Blood Pressure in Normal & Ischemic Rats (오갈피 에탄올 추출물이 뇌혈류 및 혈압에 미치는 효과)

  • Rho, Young-Ho;Jeon, Byung-Gwan;Jeong, Hyung-Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.4
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    • pp.882-886
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    • 2006
  • This study was designed to investigate the effects of Acanthopanax sessiliflorus 5.,M (ASS) on the regional cerebral blood flow (rCBF) and mean arterial blood pressure (BP) in normal rats and ischemic rats. Experimental groups of rCBF and BP in normal and ischemic rats as follows ; ALE was injected ASS leaves 45% ethyl alcohol extract, ASE was injected ASS stems 45% ethyl alcohol extract, ARE was injected ASS roots 45% ethyl alcohol extract. The results were as follows ; In normal rats, ALE and ARE significantly increased rCBF in a dose-dependent manner, but ASE significantly decreased rCBF and MABP in a dose-dependent manner, ALE increased MABP In ischemic rats, rCBF was significantly and staDly improved by ARE (10 mg/kg, i.p.) during the period of cerebral reperfusion, which was contrasted with the findings of rapid and marked increase in control group. From the above results, it was thought that all part of Acanthopanax sessiliflorus $S_{EEM}$ was effective for hemodynamics and especially ARE was more effective than other parts.

Effect of Nodus Nelumbinis Rhizomatis Extract on the Regulation of Regional Cerebral Blood Flow in Rats (흰쥐에서 우절(藕節) 추출물의 국소 뇌혈류량 조절 효과)

  • Kim, Young-Gyun;Kwon, Mi-Jung;Cho, Su-In
    • The Korea Journal of Herbology
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    • v.20 no.3
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    • pp.75-81
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    • 2005
  • Objectives : In brain disorders such as ischemic stroke, the final outcome depends largely on the duration and the degree of the ischemia as well as the susceptibility of various cell types in the affected brain region. In the present study, the effects of Nodus Nelumbinis Rhizomatis Extract(NNRe) were tested for the anti-oxidative action of rCBF. Methods : Regional cerebral blood flow(rCBF) were determined by LDF methods. LDF allows for real time, noninvasive, continuous recordings of local CBF. The LDF method has been widely used to trace hemodynamic changes in the superficial or the deep brain structures in experimental stroke research. Results : NNRe treatment showed no change on rCBF in methylene blue, ODQ and L-NNA pretreated rats. 120 minutes of MCAO and followed reperfusion, 0.1% concentration of NNR treatment improved the altered cerebral hemodynamics of cerebral ischemic by increasing rCBF. Conclusions : The ischemia/reperfusion induced oxidative stress may have contributed to cerebral damage in rats, and the present study provides clear evidences for the beneficial effect of NNR on ischemia/reperfusion induced brain injury.

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Effects of Jaeumgenby-tang adding Aurantii FructusㆍGastrodae Rhizoma on the Brain Cell and Changes of Cerebral Hemodynamics (자음건비탕가지각ㆍ천마가 뇌세포 및 뇌혈류역학 변동에 미치는 영향)

  • Im Gwang Mo;Jeong Hyun Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.1
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    • pp.64-70
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    • 2003
  • Jaeumgenby-tang(JGT) have been used in oriental medicine for many centuries as a therapeutic agent of vertigo caused by deficiency of qi(氣) and blood(血). Effect of Aurantii Fructus(AF) take off the phlegm by promoting the circulation of qi, Gastrodae Rhizoma(GR) has effects treating for headache, vertigo by calming the liver and suppressing hyperactivity of the liver-yang(陽). And, I designed to investigate whether injection of JGT adding AFㆍGR extract(JGTAG) affects cytotoxicity in vitro, cerebral hemodynamics [regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure(MABP)] in normal and cerebral ischemia rats by MCA occlusion method. The changes of rCBF and MABP were determinated by laser-doppler flowmetry(LDF), and the change of PAD was determinated by video microscope and width analyzer. The results were as follows in normal rats; JGTAG was not cytotoxicity in brain cells. And JGTAG was significantly increased rCBF, PAD and MABP. This results suggest that JGTAG increased significantly rCBF by dilating PAD. And the results were as follows in cerebral ischemic rats; The changes of rCBF and PAD were increased stably by treatment with JGTAG(10mg/kg, i.v.) during the period of cerebral reperfusion, and pretreatment with propranolol and indomethacin were increased JGT AG induced increase of rCBF and PAD during the period of cerebral reperfusion. We suggest that JGTAG has an anti-ischemic effect through the improvement of cerebral hemodynamics.