• Carbon letters
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• v.15 no.4
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• pp.295-298
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• 2014

In this work, nanoporous carbons (NPCs) were prepared by the self-assembly of polymeric carbon precursors and block copolymer template in the presence of tetraethyl orthosilicate and colloidal silica. The NPCs' pore structures and total pore volumes were analyzed by reference to $N_2$/77 K adsorption isotherms. The porosity and elemental mercury adsorption of NPCs were increased by activation with carbon dioxide. It could be resulted that elemental mercury adsorption ability of NPCs depended on their specific surface area and micropore fraction.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.48-55
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• 2010

Neural progenitor cells (NPCs) differentiate into astrocytes, neurons and oligodendrocytes, which is controlled by various factors in brain. Recent evidences suggest that small molecules modulating the proliferation and differentiation of NPCs may have therapeutic value as well as the potential use as chemical probes. Phylligenin is a lignan with anti-inflammatory activity that is isolated from the fruits of Forsythia koreana. We investigated effects of phylligenin on proliferation and differentiation of NPCs. Treatment of phylligenin decreased the number of proliferating NPCs in culture without effects on the differentiation and survival of neural cells such as neurons and astrocytes. To examine the mechanism of the decreased NPCs number, we performed cell cycle analysis. Proliferation of NPCs was decreased via G1-S transition block by phylligenin treatment, and it was mediated by the increase of p21 level. However, phylligenin did not induce apoptosis of NPCs as determined by TUNEL assay and PARP cleavage. We also found that viability of glioma cell lines such as C6 and U87MG glioma cells, but not that of primary neuron and astrocyte, was inhibited by phylligenin. These results suggest that phylligenin selectively inhibits proliferation of rapidly growing cells such as neural stem cells and glioma cells. Given that the possible role of brain tumor stem cells in the pathology of brain cancers, the inhibitory effects of phylligenin might be useful in the development of new therapeutic agents against brain cancers.

• Journal of Korea Game Society
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• v.2 no.2
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• pp.52-59
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• 2002

This paper introduces FSM, statistical FSM and NFA that are used for assigning behaviors of NPCs in computer games. We propose a new method for remedy of the weakness of previous studies. We use the method of inferencing stochastic grammars to generate NPCs behaviors. Using this method we can generate a lot of MPCs or Computer Players behaviors automatically and the games will be more enjoyable.

• Toxicological Research
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• v.27 no.2
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• pp.103-110
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• 2011

Lipotoxicity involves pathological alterations to cells and tissues in response to elevated fat levels in blood. Furthermore, this process can disturb both cellular homeostasis and viability. In the current study, the authors show that neural progenitor cells (NPCs) are vulnerable to high levels of palmitic acid (PA) a saturated fatty acid. PA was found to cause cell death associated with elevated reactive oxygen species (ROS) levels, and to reduce NPCs proliferation. To evaluate the lipotoxicity of PA in adult NPCs in the hippocampus, male C57BL/6 mice were divided into two groups and maintained on either a normal diet (ND) or PA-rich high fat diet (HFD) for 2 weeks. Interestingly, short-term PA-rich HFD feeding reduced the survival of newly generated cells in the hippocampal dentate gyrus and hippocampal brain-derived neurotrophic factor levels. These findings suggest PA has a potent lipotoxicity in NPCs and that a PA-rich HFD disrupts hippocampal neurogenesis.

• Journal of Korea Game Society
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• v.8 no.4
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• pp.95-105
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• 2008

In virtual games, Non-Playing Character(NPC)s as game elements tend to frequently communicate with game players. Although the artificial-intelligence (AI) algorithm widely used for games has been greatly developed, basic roles of NPCs have remained on the same. In a life game whose goal is to observe the actions and behaviors of the human-like NPCs, for example, their straightahead actions cause boredom. Actually, NPCs fail to display their various expressions that are characterized by humans. To make NPCs act like humans, several characters with a greater variety of characteristics need to be created. this paper proposes how NPCs both express the wide range of emotions using probability distribution and react based on their different characteristics. To verify the change of NPC actions, personalities were assigned according to the probability distribution and this algorithm was applied to a 3D game to validate the method suggested in this paper.

• Journal of Korean Neurosurgical Society
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• v.56 no.1
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• pp.1-4
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• 2014

Objective : The aims of our study are to evaluate the effect of curcumin on spinal cord neural progenitor cell (SC-NPC) proliferation and to clarify the mechanisms of mitogen-activated protein (MAP) kinase signaling pathways in SC-NPCs. Methods : We established cultures of SC-NPCs, extracted from the spinal cord of Sprague-Dawley rats weighing 250 g to 350 g. We measured proliferation rates of SC-NPCs after curcumin treatment at different dosage. The immuno-blotting method was used to evaluate the MAP kinase signaling protein that contains extracellular signal-regulated kinases (ERKs), p38, c-Jun $NH_2$-terminal kinases (JNKs) and ${\beta}$-actin as the control group. Results : Curcumin has a biphasic effect on SC-NPC proliferation. Lower dosage (0.1, 0.5, $1{\mu}M$) of curcumin increased SC-NPC proliferation. However, higher dosage decreased SC-NPC proliferation. Also, curcumin stimulates proliferation of SC-NPCs via the MAP kinase signaling pathway, especially involving the p-ERK and p-38 protein. The p-ERK protein and p38 protein levels varied depending on curcumin dosage (0.5 and $1{\mu}M$, p<0.05). Conclusion : Curcumin can stimulate proliferation of SC-NPCs via ERKs and the p38 signaling pathway in low concentrations.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.804-806
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• 1998

Most of Instrumentation and control system in Nuclear Power Plant using analog equipment has a limitations in system designing and operation. So the network based PLC application to Nuclear Power Plant has been studied so far. This paper defines the configuration and method with Prototype which are to be applied to NPCS(NSSS Process Control System) of KNGR (Korea Next Generation Reactor). It is expected that Test result of NPCS Pototype will satisfy the essential requirements in designing KNGR.

• Journal of Korea Game Society
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• v.14 no.1
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• pp.19-28
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• 2014

This paper tried to verify whether we can make NPCs generate emergent quests consistently by experiments in the persistent world of Role Playing Games where the persistent world can generate stories through interaction among game components. In this paper, we test NPC based procedural quest generation techniques assuming quest types suggested in the past research in the persistent virtual RPG world. Our system uses desire model of NPCs and dynamic resource management system to make decision of quest generation. Our decision process considers desire satisfaction, money deposit, and friendship of NPCs. These parameters are dynamically changed by quest completion status, and affect next quest generation process. This paper shows that NPCs in the persistent virtual world can generate quests based on procedural quest techniques consistently.

• Journal of KIISE
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• v.43 no.2
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• pp.222-228
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• 2016

Uniform navigation of NPCs in computer games is an important factor that can decrease the interest of game players. This problem is particularly noticeable in pathfinding when using a waypoint graph because the NPCs navigate using only predefined locations. In this paper we propose a method that enables adaptive navigations of NPCs by observing player movements. The proposed method involves modification of waypoints dynamically by observing the player's point designation and use of the modified waypoints for NPC's pathfinding. Also, we propose an algorithm to find the NPC-specific path by learning the landform preferences of players. We simulate the implemented algorithm in an RPG game made with Unity 4.0 and confirm that NPC navigations had more variety and improved according to player navigations.

• Biomolecules & Therapeutics
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• v.31 no.3
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• pp.264-275
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• 2023

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by tremors, bradykinesia, and rigidity. PD is caused by loss of dopaminergic (DA) neurons in the midbrain substantia nigra (SN) and therefore, replenishment of DA neurons via stem cell-based therapy is a potential treatment option. Astrocytes are the most abundant non-neuronal cells in the central nervous system and are promising candidates for reprogramming into neuronal cells because they share a common origin with neurons. The ability of neural progenitor cells (NPCs) to proliferate and differentiate may overcome the limitations of the reduced viability and function of transplanted cells after cell replacement therapy. Achaete-scute complex homolog-like 1 (Ascl1) is a well-known neuronal-specific factor that induces various cell types such as human and mouse astrocytes and fibroblasts to differentiate into neurons. Nurr1 is involved in the differentiation and maintenance of DA neurons, and decreased Nurr1 expression is known to be a major risk factor for PD. Previous studies have shown that direct conversion of astrocytes into DA neurons and NPCs can be induced by overexpression of Ascl1 and Nurr1 and additional transcription factors genes such as superoxide dismutase 1 and SRY-box 2. Here, we demonstrate that astrocytes isolated from the ventral midbrain, the origin of SN DA neurons, can be effectively converted into DA neurons and NPCs with enhanced viability. In addition, when these NPCs are inducted to differentiate, they exhibit key characteristics of DA neurons. Thus, direct conversion of midbrain astrocytes is a possible cell therapy strategy to treat neurodegenerative diseases.