• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.109.1-109.1
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• 2006

• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.113.2-113.2
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• 2006

• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.94.1-94.1
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• 2006

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.3
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• pp.103-109
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• 2010

Total performance is improved by minimizing the channel interference between links in wireless mesh networks (WMNs). The paper refines on the CB-CA [1] to be suitable for multi-radio multi-channel (MRMC) WMNs. The CB-CA is the cluster-based channel assignment algorithm for one radio three channel WMN based on IEEE 802.11b/g. The CB-CA does not perform the channel scanning and the channel switching between the cluster heads (CHs) and the edge gateway nodes (EGs). However, the use of co-channel for links between CHs and EGs brings the problem of channel interference among many nodes. We propose and evaluate an improved CB-CA algorithm to solve this problem in MRMC WMNs. The proposed algorithm discriminates between transmission channel and receive channel and assigns channels to each interface randomly and advertises this information to neighbor clusters in order to be assigned no-interference channel between clusters. Therefore, the proposed algorithm can minimize the interference between clusters and also improve QoS, since it can use multiple interfaces and multiple channels.

• BMB Reports
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• v.40 no.3
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• pp.302-314
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• 2007

N type calcium channels (CaV2.2) play a key role in the gating of transmitter release at presynaptic nerve terminals. These channels are generally regarded as parts of a multimolecular complex that can modulate their open probability and ensure their location near the vesicle docking and fusion sites. However, the proteins that comprise this component remain poorly characterized. We have carried out the first open screen of presynaptic CaV2.2 complex members by an antibody-mediated capture of the channel from purified rat brain synaptosome lysate followed by mass spectroscopy. 589 unique peptides resulted in a high confidence match of 104 total proteins and 40 synaptosome proteome proteins. This screen identified several known CaV2.2 interacting proteins including syntaxin 1, VAMP, protein phosphatase 2A, $G_{o\alpha}$, G$\beta$ and spectrin and also a number of novel proteins, including clathrin, adaptin, dynamin, dynein, NSF and actin. The unexpected proteins were classified within a number of functional classes that include exocytosis, endocytosis, cytoplasmic matrix, modulators, chaperones, and cell-signaling molecules and this list was contrasted to previous reports that catalogue the synaptosome proteome. The failure to detect any postsynaptic density proteins suggests that the channel itself does not exhibit stable trans-synaptic attachments. Our results suggest that the channel is anchored to a cytoplasmic matrix related to the previously described particle web.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.2
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• pp.629-648
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• 2012

Given a video stream delivering system deployed on a multicast tree, which is embedded in a multi-channel multi-radio wireless mesh network, our problem is concerned about how to allocate interference-free channels to tree links and maximize the number of serviced mesh clients at the same time. In this paper, we propose a channel allocation heuristic algorithm based on best-first search and backtracking techniques. The experimental results show that our BFB based CA algorithm outperforms previous methods such as DFS and BFS based CA methods. This superiority is due to the backtracking technique used in BFB approach. It allows previous channel-allocated links to have feasibility to select the other eligible channels when no conflict-free channel can be found for the current link during the CA process. In addition to that, we also propose a tree refinement method to enhance the quality of channel-allocated trees by adding uncovered destinations at the cost of deletion of some covered destinations. Our aim of this refinement is to increase the number of serviced mesh clients. According to our simulation results, it is proved to be an effective method for improving multicast trees produced by BFB, BFS and DFS CA algorithms.

• Journal of Ginseng Research
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• v.32 no.2
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• pp.89-98
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• 2008

There are increasing evidences in the literatures on the potential role of ginsenosides in treating cardiovascular diseases. In this article, current information about ginsenosides-mediated vascular relaxation are reviewed. From the published studies using isolated organs, cell culture systems and animal models, ginsenosides are shown to relax blood vessels and improve blood flow through diverse mechanisms, including nitric oxide release by activating eNOS phosphorylation via PI3K/Akt and/or ERK1/2 pathways in endothelial cells, induction of inducible nitric oxide synthase through activation of NF-${\kappa}$B, reducing the intracelluar Ca$^{2+}$ levels by activating Ca$^{2+}$-activated K$^{+}$ channels in vascular smooth muscle cells and reducing platelet aggregation by decreasing thromboxane A$_2$ formation and intracelluar Ca$^{2+}$in platelets. In addition, the relevant clinical trials regarding the effects of ginsenosides on the cardiovascular disease are summarized, particulary focusing on managing hypertension and improving thrombotic disorders. Finally, antagonistic effects of ginsenosides on the prostaglandin H$_2$ receptor and scavenging effects on the generation of oxygen-derived free radicals in spontaneously hypertensive rats (SHR) are discussed.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.6
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• pp.305-309
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• 2002

There are some evidences that $K^+$ efflux evoked by muscarinic stimulation is not mainly mediated by large conductance $K^+$ (BK) channels in salivary gland. In this experiment, we therefore characterised non BK channels in rat submandibular gland acinar cells and examined the possibility of agonist effect on this channel using a patch clamp technique. Two types of $K^+$ channels were observed in these cells. BK channels were observed in 3 cells from total 6 cells and its average conductance was $152{\pm}7$ pS (n=3). The conductance of the another types of $K^+$ channel was estimated as $71{\pm}7$ pS (n=6). On the basis of the conductance of this channel, we defined this channel as intermediate conductance $K^+$ (IK) channels, which were observed from all 6 cells we studied. When we increased $Ca^{2+}$ concentration of the bath solution in inside-out mode, the IK channel activity was greatly increased, suggesting this channel is $Ca^{2+}$ sensitive. We next examined the effect of carbachol (CCh) and isoproterenol on the activity of the IK channels. $10^{-5}$ M isoproterenol significantly increased the open probability (Po) from $0.08{\pm}0.02$ to $0.21{\pm}0.03$ (n=4, P<0.05). Application of $10^{-5}$ M CCh also increased Po from $0.048{\pm}0.03$ to $0.55{\pm}0.33$ (n=5, P<0.05) at the maximum channel activity. The degree of BK channel activation induced by the same concentration of CCh was lower than that of IK channels; Po value was $0.011{\pm}0.003$ and $0.027{\pm}0.005$ in control and during CCh stimulation (n=3), respectively. The result suggests that IK channels exist in salivary acinar cells and its channel activity is regulated by muscaricinic and ${\beta}-adrenergic$ agonist. We conclude that IK channels also play a putative role in secretion as well as the BK channels in rat submandibular gland acinar cells.

• Animal cells and systems
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• v.16 no.4
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• pp.269-273
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• 2012

Controlling metabolism throughout life is a necessity for living creatures, and perturbation of energy balance elicits disorders such as type-2 diabetes mellitus and cardiovascular disease. $Ca^{2+}$ plays a key role in regulating energy generation. $Ca^{2+}$ homeostasis of the endoplasmic reticulum (ER) lumen is maintained through the action of $Ca^{2+}$ channels and the $Ca^{2+}$ ATPase pump. Once released from the ER, $Ca^{2+}$ is taken up by mitochondria where it facilitates energy metabolism. Mitochondrial $Ca^{2+}$ serves as a key metabolic regulator and determinant of cell fate, necrosis, and/or apoptosis. Here, we focus on $Ca^{2+}$ transport from the ER to mitochondria, and $Ca^{2+}$-dependent regulation of mitochondrial energy metabolism.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.47-47
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• 2001

Opening of $Ca^{2＋}$ -channels represents the final common pathway for insulin secretion in pancreatic beta-cells and related cell lines. We investigated voltage-sensitive calcium channels (VSCCs) and insulin secretion in RINm5F, an insulinoma cell line derived from rat pancreatic beta-cells. Several types of VSCCs were identified in RINm5f cells： dihydropyridine-sensitive L-type, $\omega$-conotoxin GVIA-sensitive N-type, $\omega$-agatoxin IVA-sensitive P-type channels, and $\omega$-conotoxin MVIIC sensitive Q-type channels.(omitted)