• The Korean Journal of Physiology and Pharmacology
• /
• 제15권3호
• /
• pp.171-177
• /
• 2011

Tonic smooth muscle exhibit the latch phenomenon: high force at low myosin regulatory light chains (MRLC) phosphorylation, shortening velocity (Vo), and energy consumption. However, the kinetics of MRLC phosphorylation and cellular activation in phasic smooth muscle are unknown. The present study was to determine whether $Ca^{2+}$-stimulated MRLC phosphorylation could suffice to explain the agonist- or high $K^+$-induced contraction in a fast, phasic smooth muscle. We measured myoplasmic [$Ca^{2+}$], MRLC phosphorylation, half-time after step-shortening (a measure of Vo) and contractile stress in rabbit urinary bladder strips. High $K^+$-induced contractions were phasic at both $22^{\circ}C$ and $37^{\circ}C$: myoplasmic [$Ca^{2+}$], MRLC phosphorylation, 1/half-time, and contractile stress increased transiently and then all decreased to intermediate values. Carbachol (CCh)-induced contractions exhibited latch at $37^{\circ}C$: stress was maintained at high levels despite decreasing myoplasmic [$Ca^{2+}$], MRLC phosphorylation, and 1/half-time. At $22^{\circ}C$ CCh induced sustained elevations in all parameters. 1/half-time depended on both myoplasmic [$Ca^{2+}$] and MRLC phosphorylation. The steady-state dependence of stress on MRLC phosphorylation was very steep at $37^{\circ}C$ in the CCh- or $K^+$-depolarized tissue and reduced temperature flattend the dependence of stress on MRLC phosphorylation compared to $37^{\circ}C$. These data suggest that phasic smooth muscle also exhibits latch behavior and latch is less prominent at lower temperature.

• 대한핵의학회지
• /
• 제34권4호
• /
• pp.312-321
• /
• 2000

목적: 발작기 뇌 SPECT에서 교차소뇌과혈류를 통하여 내측성과 외측성 측두엽간질을 감별할 수 있는지 그 임상적 유용성 여부와 발생에 영향을 줄 수 있는 요인을 알아보고자 하였다. 대상 및 방법: 침습적 뇌파검사와 수술 후 경과로 확진된 59명의 측두엽간질 환자를 대상으로 하였다. 모든 예에서 발작기 Tc-99m HMAPO 뇌 SPECT를 시행하였고 평균주사시간은 비디오로 관찰한 간질뇌파시작으로 부터 $32.6{\pm}19.5$초였다. 교차소뇌과혈류와 관련이 있는 요인으로 측두엽간질의 아형(내측성 또는 외측성 측두엽간질), 발작기 SPECT에서 간질병소의 전파되는 유형(측두엽에 국한된 경우, 주변대뇌피질로 전파된 경우 및 반대측 대뇌로 전파된 경우), 환자의 연령, 발작시점으로부터 주사시간의 네 가지 지표를 포함하여 다중로짓회귀분석을 하였다. 결과: 교차소뇌과혈류는 전체적으로 31% (18/59)에서 관찰되었고 내측성 측두엽간질환자는 29% (15/51), 외측성 측두엽간질환자는 38% (3/8)였다. 다중로짓회귀분석결과 SPECT에서 간질병소의 전파되는 유형(p=0.01)과 환자의 나이(p=0.02)가 가장 유의한 결과를 보였다. 즉 측두엽간질에 국한된 경우보다 주변이나 반대측으로 전파된 경우일수록, 환자의 나이가 어릴수록 관련이 있었다. 그러나 내외측 측두엽간질의 아형과 주사시간은 통계적 유의성을 갖지 못했다. 결론: 발작기 SPECT에서 내외측측두엽간질을 구분하는데 교차소뇌과혈류는 도움을 주지 못하며 발생과 관련이 있는 요인은 간질병소의 전파유형이나 환자의 나이였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제11권1호
• /
• pp.61-77
• /
• 2017

The most challenging issues in the multi-channel MAC of the IEEE 1609.4 standard is how to handle the dynamic vehicular traffic condition with a high mobility, dynamic topology, and a trajectory change. Therefore, dynamic channel coordination schemes between CCH and SCH are required to provide the proper bandwidth for CCH/SCH intervals and to improve the quality of service (QoS). In this paper, we use a Markov model to optimize the interval based on the dynamic vehicular traffic condition with high mobility nodes in the multi-channel MAC of the IEEE 1609.4 standard. We evaluate the performance of the three-dimensional Markov chain based on the Poisson distribution for the node distribution and velocity. We also evaluate the additive white Gaussian noise (AWGN) effect for the multi-channel MAC coordination scheme of the IEEE 1609.4 standard. The result of simulation proves that the performance of the dynamic channel coordination scheme is affected by the high node mobility and the AWGN. In this research, we evaluate the model analytically for the average delay on CCHs and SCHs and also the saturated throughput on SCHs.

• 태양에너지
• /
• 제10권2호
• /
• pp.38-43
• /
• 1990

본 연구는 염화칼슘6수화물($CaCl_2{\cdot}6H_2O$)을 온돌판넬에 적용하여 가열시간에 따른 잠열재판넬의 축열 및 방열특성을 조사하기 위하여 같은 크기의 실험동($1.8m^L{\times}1.8m^W{\times}1.8m^H$)을 지었다. 잠열재판넬에 적용할 알루미늄 용기는 $1.6cm^T{\times}9cm^W{\times}80cm^H$ 크기로 제작하여 염화칼슘6수화물(1.25kg)을 충진시켰다. 잠열재인 염화칼슘6수화물을 넣은 온돌판넬은 실내공기온의 변화폭을 줄이고, 잠열재의 상변화과정에서 방열되는 시간은 축열에 필요한 가열시간의 $2{\sim}4$배 정도였다.

• International Journal of Oral Biology
• /
• 제41권3호
• /
• pp.119-123
• /
• 2016

Acetylcholine receptors (AChR) including muscarinic and nicotinic AChR are widely expressed and mediate a variety of physiological cellular responses in neuronal and non-neuronal cells. Notably, a functional cholinergic system exists in oral epithelial cells, and nicotinic AChR (nAChR) mediates cholinergic anti-inflammatory responses. However, the pathophysiological roles of AChR in periodontitis are unclear. Here, we show that activation of AChR elicits increased cytosolic $Ca^{2+}([Ca^{2+}]_i)$, transient cytotoxicity, and induction of receptor activator of nuclear factor kappa-B ligand (RANKL) expression. Intracellular $Ca^{2+}$ mobilization in human gingival fibroblast-1 (hGF-1) cells was measured using the fluorescent $Ca^{2+}$ indicator, fura-2/AM. Cytotoxicity and induction of gene expression were evaluated by measuring the release of glucose-6-phosphate dehydrogenase and RT-PCR. Activation of AChR in hGF-1 cells by carbachol (Cch) induced $[Ca^{2+}]_i$ increase in a dose-dependent manner. Treatment with a high concentration of Cch on hGF-1 cells caused transient cytotoxicity. Notably, treatment of hGF-1 cells with Cch resulted in upregulated RANKL expression. The findings may indicate potential roles of AChR in gingival fibroblast cells in bone remodeling.

• Nuclear Engineering and Technology
• /
• 제54권5호
• /
• pp.1909-1913
• /
• 2022

This work shows the technical feasibility to obtain uranium tetrafluoride through an electrochemical mercury cell. This technique represents a custom scaling-up methodology from our previous studies to obtain UF₄ using the dropping mercury electrode cell. The UF₄ products were obtained from natural UF₆ gas, which was hydrolyzed to obtain a 50 g/L UO₂F₂ solution. The electrolysis cell was made using a mercury reservoir, to reach UF₄ production rates of 1 Kg UF₄/day. This custom design allowed a stable UF₄ production thanks to the mercury cathode, which do not permit the accumulation of solid products in its surface. The cell was tested using current densities from 5.000 to 17.500 A/m² and temperatures from 25 to 65 ℃. The maximum current efficiency achieved under these conditions was 80%. The UF₄ powders possessed spherical morphology, with diameters between 20 and 80 ㎛. Compared to the SnCl₂ precipitation, this process did not allow preferential growth of the precipitates. This improved the compaction of the UF₄ - Mg powders mixtures, with densities between 3.0 and 3.5 g/cm³. The purity of the UF₄ products was over 98%.

• E2M - 전기 전자와 첨단 소재
• /
• 제9권3호
• /
• pp.265-269
• /
• 1996

We have studied the effect of the mesogenic core of nematic liquid crystals (NLCs) for polar (out-of-plane tilt) anchoring strength and surface order parameter on rubbed polyimide (PI) surfaces. The order of polar anchoring strength for NLCs on rubbed PI surfaces is 5CB > PCH5 > CCH5. From the above results, we suggest that the polar anchoring strength depends on the polarizability of the NLCs. The surface order parameter for NLCs is 5CB > PCH5 > CCH5 on rubbed PI surfaces. We conclude that the polar anchoring strength is strongly related to the surface order parameter on rubbed PI surfaces.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1995년도 추계학술대회 논문집
• /
• pp.265-268
• /
• 1995

We have studied the effect of the mesogenic core of nematic liquid crystals (NLCs) for polar (out-of-plane tilt) anchoring strength and surface order parameter on rubbed polyimide (PI) films. The order of polar anchoring strength for NLCs on rubbed PI films is 5CB > PCH5 > CCH5. This order is the same for all rubbing strengths investigated. The surface order parameter for NLCs is 5CB > PCH-5 > CCH5 on rubbed PI films. From these results, we suggest that the polar anchoring strength is strongly related to the surface order parameter.

• 한국수의병리학회:학술대회논문집
• /
• 한국수의병리학회 2003년도 추계학술대회초록집
• /
• pp.53-53
• /
• 2003

This benign canine histiocytoma was the most common single tumor type, followed lipoma, adenoma, soft tissue sarcoma, mast cell tumor and lymphosarcoma [2]. Canine cutaneous histiocytoma (CCH) most commonly occur as solitary lesions, head and pinnae are prefermential sites, that undergo spontaneous regression. The histologic appearance varies greatly, depending on the age of the lesion and the degree of necrosis and secondary inflammation. The age-specific incidence rate for CCH drops precipitously after 3 years, although histiocytomas occur in dogs of all ages [5]. Their etiology and pathogenesis are unknown. This case reports the gross and histopathological findings of canine cutaneous histiocytoma of observed in a young dog with localized calcification of lingual muscle. (omitted)

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2023년도 춘계학술발표대회
• /
• pp.310-311
• /
• 2023

우리나라 범죄율이 지속적으로 상승함에 따라 시민들의 불안은 커져가고 있다. 특히 밤길에 혼자 다니는 것을 불안하게 느끼는 '밤길 불안'이 심해지는 요즘, 안전한 길을 제공하여 사회적 불안감을 낮춰주는 서비스의 필요성이 요구된다. 이에 본 논문에서는 안전 데이터를 활용하여 사용자에게 안전한 길을 안내해주는 애플리케이션을 개발하여 사회 안정성과 공익성에 기여하고자 한다.