• The Korean Journal of Physiology and Pharmacology
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• 제24권4호
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• pp.349-362
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• 2020

Temperature affects the firing pattern and electrical activity of neurons in animals, eliciting diverse responses depending on neuronal cell type. However, the mechanisms underlying such diverse responses are not well understood. In the present study, we performed in vitro recording of abdominal ganglia cells of Aplysia juliana, and analyzed their burst firing patterns. We identified atypical bursting patterns dependent on temperature that were totally different from classical bursting patterns observed in R15 neurons of A. juliana. We classified these abnormal bursting patterns into type 1 and type 2; type 1 abnormal single bursts are composed of two kinds of spikes with a long interspike interval (ISI) followed by short ISI regular firing, while type 2 abnormal single bursts are composed of complex multiplets. To investigate the mechanism underlying the temperature dependence of abnormal bursting, we employed simulations using a modified Plant model and determined that the temperature dependence of type 2 abnormal bursting is related to temperature-dependent scaling factors and activation or inactivation of potassium or sodium channels.

• Macromolecular Research
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• 제10권6호
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• pp.304-310
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• 2002

In a recent study by the same authors using a DMTA (Dynamic Mechanical Thermal Analyzer), it was found that the 4-aminobenzoic arid (ABA) molecules acted as either a neutralizing agent, or a plasticizer, or a filler, depending on the order of mixing of poly(styrene-co-styrenesulfonic acid) (PSSA), ABA, and NaOH. Subsequent to that study, we here pursued the same topic, i.e., the effect of the addition of CsOH (instead of NaOH) and ABA on the morphology of PSSA, but this time, by using a small-angle X-ray scattering (SAXS) technique. In line with the previous results, the present study with the SAXS technique verified that the order of mixing has a significant effect on the morphology of ionomers. In addition, with the SAXS data and the density values of the ionomers, we attempted to calculate both the number of sulfonate ionic groups per multiplet and the size of the multiplet of the ionomer.

• Bulletin of the Korean Chemical Society
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• 제7권4호
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• pp.267-271
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• 1986

The ionomeric blend and the ionic aggregation studies by using a Fourier-transform infrared spectroscopy(FT-IR) are presented. Two ionomers were prepared, one is barium polyacrylate and the other is barium polystyrenesulfonate. The blend of the two ionomers of the barium salts shows intermolecular ionic interaction between the carboxylated ionomer and the sulfonated ionomer. This interaction leads to considerable differences between the spectrum of the blend and the sum of the spectra of the pure ionomers. From our results, it is shown that ionic interactions must play an important role in the compatibility of the two ionomers. In the ionic aggregation study, the bands due to asymmetric stretching mode of carboxylate anion(COO-) in the carboxylated ionomer and the ionomer blend increase in intensity with increasing the divalent barium cations. These results indicate the formation of ion pairs. The doublet due to the asymmetric stretching modes of the carboxylate anion(COO-) is concerned with a sort of local structure found in the ion aggregation. By considering a possible structure for multiplets in the blend, the spectral splitting and the frequency shift are well explained.

• 지구물리와물리탐사
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• 제13권1호
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• pp.109-117
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• 2010

소니 플레이스테이션3 (PS3) 비디오 게임 콘솔을 이용하여 대용량자료에 고성능 계산을 적용시키기 위하여 개인용컴퓨터 (PC) 의 윈도우 시스템과 PS3로 구성된 하이브리드 시스템을 제작하였다. 이 시스템의 성능을 검증하기 위해 파형모양의 유사도를 이용하여 미세지진의 멀티플렛을 알아내는 실시간 멀티플렛 식별자 (RTMI)를 수행하여보았다. RTMI의 핵심 알고리즘인 상호상관 계산은 PS3 플랫폼에 최적화 되었고 자료의 압출력을 포함하는 다른 계산들은 PC 상에서 수행되었다. 이 경우에 알고리즘의 핵심 부분이 원래의 경우보다 50 배 이상 빨리 수행되어 결과적으로 개발된 시스템은 과거 400개의 신호밖에 처리하지 못하던 것을 총 2100개까지의 미소진통 신호등을 처리 할 수 있게 하였다. 이 결과는 자료전송시간이 계산시간에 비해 무시할 수 있는 한 PS3를 이용한 대용량 자료의 고성능 계산이 가능하다는 것을 잘 보여주고 있다.

• 대한화학회지
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• 제25권3호
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• pp.190-198
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• 1981

삼페닐-9-티오크잔텐닐포스포니움 과염소산염과 삼-오르토-메톡시페닐-9-티오크잔텐닐포스포니움 과염소산염과는 대조적으로 삼-n-부틸-9-티오크잔텐닐포스포니움 과염소산염과 삼벤질-9-티오크잔텐닐포스포니움 과염소산염은 각각 ${\delta}5.58$ppm과 ${\delta}5.70$ ppm 에서 methine 양성자에 해당하는 이중상을 보여주었다. 이 값은 9-아릴티오크잔틴의 상응값 (${\delta}5.05$~5.30)보다 다소 큰 값이나 방향족화합물의 양성자의 값과는 분명히 차이가 난다. 이 결과는 삼아릴-9-티오크잔텔닐포스포니움 과염소산염의 methine 양성자가 낮은 장으로 이동한 원인이 전자가 부족한 인원자에 의한 유발 효과때문이 아니라 인에 결합된 세개의 아릴기의 상자기성 벗김 효과에 의한 것임을 의미한다.

• 한국응용과학기술학회지
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• 제22권4호
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• pp.323-331
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• 2005

Fatty acid compositions of the seed oils of P. schinseng, A. continentalis and A. sessiliflorus, were analyzed by gas chromatography (GC) equipped with a capillary column. A large unusual peak was observed just before the peak corresponding to oleic acid $(cis-9-C_{18:1})$. This unknown fatty acid was isolated by silver ion chromatography and then derivatized into the picolinyl ester. The mass spectrum of the picolinyl ester showed molecular ion at m/z=373 with other diagnostic ions such as m/z=178, 218, 232, 246, 274, 288, 302 and 344. Characteristic absorption peaks at $720\;cm^{-1}$, $1640\;cm^{-1}$ and $3010\;cm^{-1}$ in IR spectrum indicated the presence of cis-configurational double bond in the molecule. The $^1H-NMR$ spectrum of this acid gave two quintets centered at ${\delta}1.638$ (2H, C-3) and ${\delta}1.377$ (2H, C-4), and two multiplets centered at ${\delta}2.022{\sim}2.047$ (2H, C-5) and ${\delta}2.000{\sim}2.022$ (2H, C-8), and multiplet signals of olefinic protons centered at ${\delta}5.3015{\sim}5.3426$ (C-6, J=9.5 Hz) and ${\delta}\;5.3465{\sim}5.3877$ (C-7, J=9.5 Hz). The $^13C-NMR$ spectrum showed 18 carbon resonance signals including an overlapped signal at ${\delta}29.7002$ for C-12 and ${\delta}29.6520$ for C-13 (or they can be reversed), and other highly resolved signals at ${\delta}33.950$, ${\delta}24.558$, ${\delta}26.773$ and ${\delta}27.205$ due to C-2, C-3, C-5 and C-8 of a ${\Delta}^6-octadecenoic$ acid, respectively. From analysis results this unknown fatty acid could be identified as cis-6-octadecenoic acid. The seed oils of P. schinseng and A. sessiliflorus contained petroselinic acid (59.7%, 56.0%), oleic acid (18.3%, 6.1%) and linoleic acid (16.2%, 30.4%) with small amount of palmitic acid (3.0%, 3.1%) while the seed oil of A. continentalis comprised mainly oleic acid (30.2%), petroselinic acid (29.0%), linoleic acid (24.1%) and palmitic acid (13.1%).