• Title/Summary/Keyword: Spiking

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Early Changes after Death of Plaice, Paralichthys olivaceus Muscle -1. Relationship between Early Changes after Death and Temperature Dependency- (넙치(Paralichthys olivaceus)육의 사후 조기 변화 -1. 사후 조기 변화와 온도 의존성의 관계-)

  • KIM Yuck-Yong;CHO Young-Je
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.25 no.3
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    • pp.189-196
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    • 1992
  • To know the extension effect of storage temperature on the pre-rigor period of plaice, Paratichthys olivaceus muscle, the relationship between early changes after death and temperature dependency was studied. Killed plaices instantly with spiking at the brain were stored at $-3^{\circ}C,\;0^{\circ}C,\;5^{\circ}C\;and\;10^{\circ}$ used in studying the changes in rigor Index, ATP and its related compounds, lactate contents and K-value. The most shortest onset time of rigor-mortis and full rigor was revealed in the sample stored at $-3^{\circ}C$ among the all samples, where rigor-mortis began at 4hrs after spiking and maximum tension was attained after 28hrs. However, in case of fresh plaice muscle stored at $10^{\circ}C$, the onset of rigor-mortis and full rigor were retarded to 14hrs and 52hrs after spiking. ATP in sample stored at $5^{\circ}C\;and\;10^{\circ}C$ were decomposed slowly than sample at $0^{\circ}C\;-3^{\circ}C $ and within 35hrs storage. The fastest rate and the maximum content of lactate accumulation were showed in sample stored at $-3^{\circ}$ among the all samples. The correlation coefficient(r) between the rate of rigor mortis and ATP breakdown, rigor mortis and lactate accumulation, and ATP breakdown and lactate accumulation were -0.981946, 0.965044, and -0.964728, respectively. Freshness of $-3^{\circ}C$ stored samples was maintained for the longest time compared with other stored samples. The times reached around $20\%$ of K-value were 240hrs for samples stored at $-3^{\circ}C,\;96hrs\;for\;0^{\circ}C\;samples,\;71hrs\;for\;5^{\circ}C\;samples,\;and\;22hrs\;for\;10^{\circ}C$ samples. Samples stored at $-3^{\circ}C,\;and\;0^{\circ}C$ were showed higher temperature dependency on rate of rigor-mortis, ATP breakdown, and lactate accumulation than $5^{\circ}C\;and\;10^{\circ}C$ stored samples, but those samples have a lower temperature dependency on K-value.

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The Effect of Heat on the Spiking Patterns of the Cells in Aplysia (군소 세포의 발화 형태에 미치는 열자극 효과)

  • Hyun, Nam-Gyu
    • Progress in Medical Physics
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    • v.18 no.2
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    • pp.73-80
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    • 2007
  • Fruitful findings have been produced from five out of sixty cells which were obtained from each 63 individual Aplisia caught at the Jeju coast. Spiking patterns of three out of five cells, such as relaxation oscillator, bursting within a short time of the inter-burst interval, chaotic bursting, period doubling sequences, bursting with long trains of action potentials separated by short silent periods, regular repeated beating or elliptic bursting, and silent states had been changed in order as the temperature was lowered to $10^{\circ}C\;from\;32^{\circ}C$. In the intervals of every about 40 minutes repeated ups and downs of temperature produced similar firing patterns at the allowable temperature ranges. The other two cells showed difference from these. The amplitudes of the action potentials of the two cells will not be highly decreased in 24 hours. Average spike frequencies, the inter-burst interval, peak to peak spike amplitude of action potentials, minimum potential values are compared and analyzed by using the computer programme. The spike frequencies according to temperature show the distribution of bell type, with maximal spike frequencies at intermediate temperatures and minimal ones at either end. The most common pattern consist of high spike frequency during failing and low one during rising temperatures.

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A Study on the MEG Imaging (MEG 영상진단 검사에 관한 연구)

  • Kim, Jong-Gyu
    • Korean Journal of Clinical Laboratory Science
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    • v.37 no.2
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    • pp.123-128
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    • 2005
  • Magnetoencephalography (MEG) is the measurement of the magnetic fields produced by electrical activity in the brain, usually conducted externally, using extremely sensitive devices such as Superconducting Quantum Interference Device (SQUID). MEG needs complex and expensive measurement settings. Because the magnetic signals emitted by the brain are on the order of a few femtoteslas (1 fT = 10-15T), shielding from external magnetic signals, including the Earth's magnetic field, is necessary. An appropriate magnetically shielded room is very expensive, and constitutes the bulk of the expense of an MEG system. MEG is a relatively new technique that promises good spatial resolution and extremely high temporal resolution, thus complementing other brain activity measurement techniques such as electroencephalography (EEG), positron emission tomography (PET), single-photon emission computed tomography (SPECT) and functional magnetic resonance imaging (fMRI). MEG combines functional information from magnetic field recordings with structural information from MRI. The clinical uses of MEG are in detecting and localizing epileptic form spiking activity in patients with epilepsy, and in localizing eloquent cortex for surgical planning in patients with brain tumors. Magnetoencephalography may be used alone or together with electroencephalography, for the measurement of spontaneous or evoked activity, and for research or clinical purposes.

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Long-Term Potentiation of Excitatory Synaptic Strength in Spinothalamic Tract Neurons of the Rat Spinal Cord

  • Hur, Sung Won;Park, Joo Min
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.6
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    • pp.553-558
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    • 2013
  • Spinal dorsal horn nociceptive neurons have been shown to undergo long-term synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD). Here, we focused on the spinothalamic tract (STT) neurons that are the main nociceptive neurons projecting from the spinal cord to the thalamus. Optical technique using fluorescent dye has made it possible to identify the STT neurons in the spinal cord. Evoked fast mono-synaptic, excitatory postsynaptic currents (eEPSCs) were measured in the STT neurons. Time-based tetanic stimulation (TBS) was employed to induce long-term potentiation (LTP) in the STT neurons. Coincident stimulation of both pre- and postsynaptic neurons using TBS showed immediate and persistent increase in AMPA receptor-mediated EPSCs. LTP can also be induced by postsynaptic spiking together with pharmacological stimulation using chemical NMDA. TBS-induced LTP observed in STT neurons was blocked by internal BAPTA, or $Ni^{2+}$, a T-type VOCC blocker. However, LTP was intact in the presence of L-type VOCC blocker. These results suggest that long-term plastic change of STT neurons requires NMDA receptor activation and postsynaptic calcium but is differentially sensitive to T-type VOCCs.

Feasibility of monitoring of fluoroquinolones residual through feather analysis in broilers (육계에서 깃털을 이용한 플루오르퀴놀론계 잔류 모니터링 가능성 조사)

  • Kim, Jae-Ho;Kim, Mi-Hee;Ahn, Gil-Ho
    • Korean Journal of Veterinary Service
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    • v.43 no.3
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    • pp.189-196
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    • 2020
  • This study was conducted to analyze feasibility of monitoring of fluoroquinolnes residual through feather analysis in broilers. The calibration curve showed good linearity (r2≥0.99) within the concentration range of 1~100 ㎍/kg. The limit of detection (LOD) and limit of quantification (LOQ) were validated at ≤0.66 and ≤1.99 ㎍/kg in broiler feather, respectively. The recoveries in feather samples ranged from 94.6 to 114.4% (5.1-15.8% RSD) at the 5 to 20 ㎍/kg spiking levels. The proposed new analytical method proved to be suitable and effective for fluoroquinolnes determination. We also monitored fluoroquinolones residue in 36 samples (broiler that were slaughtered in Gyonggi-do) using this method. Among tested feather samples, enrofloxacin and ciprofloxacin were detected in all samples. In muscle samples, enrofloxacin was detected in 20 (55.6%) samples and ciprofloxacin was not detected.

Pd/Ge/Ti/pt Ohmic contact to InGaAs for Heterojunction Bipolar Transistors(HBTs) (이종접합 쌍극자 트랜지스터(HBT)의 에미터 접촉층으로 사용되는 InGaAs에 대한 Pd/Ge/Ti/Pt의 오믹 접촉 특성)

  • 김일호;장경욱;박성호(주)가인테크
    • Journal of the Korean Vacuum Society
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    • v.10 no.2
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    • pp.219-224
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    • 2001
  • Pd/Ge/Ti/Pt ohmic contact to n-type InCaAs was investigated. Minimum specific contact resistivity of $3.7\times10^{-6}\; \Omega\textrm{cm}^2$ was achieved by rapid thermal annealing at $400^{\circ}C$ for 10 seconds. This was related to the formation of Pd-Ge compounds and the in-diffusion of Ge atoms to InGaAs surface. However, the specific contact resistivity increased slightly to $low-10^5\; \Omega\textrm{cm}^2$ in the case of longer annealing time. Superior ohmic contact and non-spiking planar interface between ohmic materials and InGaAs were maintained after annealing at high temperature. Therefore, this thermally stable ohmic contact system is a promising candidate for compound semiconductor devices.

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A study on the robot for mining of underground resources (지하자원 채굴용 로봇의 연구)

  • Noh, Jong-Ho;Shin, Suk-Shin;Park, Jong-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.4
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    • pp.399-403
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    • 2013
  • Mining diggers have been substituted with the robots for the mining works in dangerous and narrow tunnel, and those demands are increased in nowadays. In this study, experimental research on the remote controlled robots to perform after the development of the robot. According to the test results, performances of the developed robot and its working devices have been modified several times. It has been considered that the robot keeps its optimum performance in states as follows; driving speed 1.0 km/h, crawl angle $10^{\circ}$, spiking cycle 500bpm and breaking power $30kg_fm$. And also it has been found that sufficient cooling for the robot's working parts is essential to extend those working periods longer than 3 hours steadily under rating condition.

Measurement of Free Polysaccharide in Tetanus Toxoid-Conjugate Vaccine Using Antibody/Ammonium Sulfate Precipitation

  • Yoo, Tae-Hyeon;Kim, Hyun-Sung;Park, Sung-Sik;Bang, Eun-Young;Oh, Yong-K.;Kim, Li-Seop;Kim, Hun;Hur, Byung-Ki;Ryu, Yeon-Woo;Kim, Jong-Su
    • Journal of Microbiology and Biotechnology
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    • v.13 no.3
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    • pp.469-472
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    • 2003
  • A method that effectively precipitates capsular polysaccharide of Haemophilus influenzae type b (polyribosylribitol phosphate, PRP) conjugated to tetanus toxoid (TT), PRP TT in a liquid vaccine has been developed to measure free PRP present in TT-conjugate vaccine. The method involves adding anti-TT antibody and ammonium sulfate to precipitate PRP-TT conjugate and measuring free PRP in tile supernatant. This new method provides a complete precipitation of the total PRP-TT, and provides an accurate and reproducible measurements of free PRP. The accuracy of the assay was confirmed by spiking known amounts of unconjugated PRP to PRP-TT conjugate, and the new method was found to have no effect on free PRP while precipitating PRP-TT. The published acid precipitation method did not produce reproducible results due to incomplete precipitation of PRP-TT, especially when the vaccine is formulated in a salt-buffered solution.

Pd/Ge/Pd/Ti/Au Ohmic Contact for Application to AlGaAs/GaAs HBT (AIGaAs/GaAs HBT 응용을 위한 Pd/Ge/Pd/Ti/Au 오믹 접촉)

  • 김일호;박성호(주)가인테크
    • Journal of the Korean Vacuum Society
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    • v.11 no.1
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    • pp.43-49
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    • 2002
  • Pd/Ge/Pd/Ti/Au ohmic contact to n-type InGaAs was investigated with rapid thermal annealing conditions. Minimum specific contact resistivity of $1.1\times10^{-6}\Omega\textrm{cm}^2$ was achieved after annealing at $400^{\circ}C$/10sec, and a ohmic performance was degraded at higher annealing temperature due to the chemical reaction between the ohmic contact materials and the InGaAs substrate. However, non-spiking planar interface and relatively good ohmic contact($high-10^{-6};{\Omega}\textrm{cm}^2$) were maintained. This ohmic contact system is expected to be a promising candidate for compound semiconductor devices.

The Effects of Metal Structure on the Junction Stability of Sub-micron Contacts Using Selective CVD-W Plug (금속 구조 변화에 따른 선택 화학기상증착 W Plug의 접합 신뢰성 연구)

  • 최경근;김춘환;박흥락;고철기
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.5
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    • pp.94-100
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    • 1994
  • The junction failure mechanism of W plugs has not been fully understood while the selective W deposition has been widely used for plugging interconnection lines. In this paper, the thermal stability and junction failure mechanism of sub-micron contacts using selective CVD-W plugs were intensively studied with the metal lines of AISiCu, Ti/AISiCu and TiN/AISiCu. The experimental results showed that the contact chain resistance and leakage current in the AISiCu and Ti/AISiCu metallizations were significantly degraded after annealing. From the SEM analysis, it was found that the junction spiking, due to the Al atoms diffusion along the porous interface between selective CVD-W and contactside wall, caused the junction failure. In constast, there was no degradation of the contact resistance and junction leakage current in TiN/AISiCu metal structu-re. It is believed that the TiN barrier layer could prevent AI(Ti) atoms Fromdiffusing. Therefore, TiN barrier between W plug and Al should be used to impro-ve the thermal stability of sub-micron contacts using the selective CVD-W plugs.

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