• Archives of Pharmacal Research
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• v.26 no.4
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• pp.301-305
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• 2003

Nitric oxide (NO) is an important bioactive agent that mediates a wide variety of physiological and pathophysiological events. NO overproduction by inducible nitric oxide synthase (iNOS) results in severe hypotension and inflammation. This investigation is part of a study to discover new iNOS inhibitors from medicinal plants using a macrophage cell culture system. Two sesquiterpenes (1 and 2) were isolated from Artemisia iwayomogi (Compositae) and were found to inhibit NO synthesis ($IC_{50} 3.64 \mu g/mL and 2.81 \mu$g/mL, respectively) in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Their structures were identified as 3-Ο-methyl-iso-secotanapartholide (1) and iso-secotanapartholide (2). Compounds 1 and 2 inhibited the LPS-induced expression of the iNOS enzyme in the RAW 264.7 cells. The inhibition of NO production via the down regulation of iNOS expression may substantially modulate the inflammatory responses.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.134-137
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• 2000

We applied the ICA method to separate the ventricle and tissue components and to extract left ventricular input function from the H$_2$$^{15}$ O myocardial PET under the assumption that the elementary activities of ventricular pools and myocardium were spatially independent, and that the mixture of them composed dynamic PET frames. ICA-generated left ventricular input functions were compared with the ROI-generated ones, and also with the invasively derived arterial blood samples. Moreover, the rMBF calculated with the ICA-generated input functions and single compartment model was correlated with the results obtained with the radiolabeled microspheres.

• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.200-200
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• 2005

• The Journal of Korea Robotics Society
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• v.5 no.3
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• pp.231-239
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• 2010

For indoor mobile robots, the performance of autonomous navigation is affected by a variety of factors. In this paper, we focus on the characteristics of indoor absolute positioning systems. Two commercially available sensor systems are experimentally tested under various conditions. Mobile robot navigation experiments were carried out, and the results show that resultant performance of navigation is highly dependent upon the characteristics of positioning systems. The limitations and characteristics of positioning systems are analyzed from both quantitative and qualitative point of view. On the basis of the analysis, the relationship between the positioning system characteristics and the controller design are presented.

• Applied Microscopy
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• v.46 no.1
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• pp.14-19
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• 2016

Currently, focused ion beams (FIB) are widely used for specimen preparation in atom probe tomography (APT), which is a three-dimensional and atomic-scale compositional analysis tool. Specimen preparation, in which a specific region of interest is identified and a sharp needle shape created, is the first step towards successful APT analysis. The FIB technique is a powerful tool for site-specific specimen preparation because it provides a lift-out technique and a controllable manipulation function. In this paper, we demonstrate a general procedure containing the crucial points of FIB-based specimen preparation. We introduce aluminum holders with moveable pin and an axial rotation manipulator for specimen handling, which are useful for flipping and rotating the specimen to present the backside and the perpendicular direction. We also describe specimen preparation methods for nanowires and nanopowders, using a pick-up method and an embedding method by epoxy resin, respectively.

• Bulletin of the Korean Chemical Society
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• v.33 no.1
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• pp.305-308
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• 2012

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3085-3088
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• 2014

• Journal of Korean Neurosurgical Society
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• v.47 no.1
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• pp.71-73
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• 2010

A 28-year-old woman was referred to our hospital with a sudden, very severe headache. Brain computed tomographic angiography showed a saccular cerebral aneurysm at the bifurcation of the left middle cerebral artery and infraoptic courses of both anterior cerebral arteries. The anterior cerebral arteries were seen to arise from the ipsilateral internal cerebral arteries at the level of the origin of the ophthalmic artery, passed underneath the ipsilateral optic nerve, and turned upward at ventral portion of the optic chiasm. Infraoptic course of the proximal anterior cerebral artery is an extremely rare anomaly and is often associated with cerebral aneurysms. We report the clinical features, radiological findings, and possible genesis of this anomaly with a literature review.

• Journal of Korean Neurosurgical Society
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• v.47 no.2
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• pp.137-139
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• 2010

A subarachnoid hemorrhage (SAH) associated with negative finding on four-vessel angiography is seen in 5 to 30% of patients with intracranial SAH. A previously silent lesion in the spinal canal may be responsible for the angiographically negative finding for cause of intracranial SAH. We report a case of upper cervical (C1-2) intradural schwannoma presenting with acute intracranial SAH. Repeated cerebral angiographic studies were negative, but cervical magnetic resonance imaging study and tissue pathology revealed a intradural-extramedullary schwannoma in C1-2 level. This case illustrates the importance of a high index of clinical suspicion for spinal disease in angiographically negative intracranial SAH patients.

• Nuclear Engineering and Technology
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• v.35 no.3
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• pp.214-225
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• 2003

A teleoperated manipulator system has been developed for remote handling of the spent fuel bundles. A heavy-duty power manipulator with high reduction ratio joints is used for the slave manipulator in the developed system since the handling tasks of the spent fuel bundles need power. Also, the universal type master manipulator, which has force reflecting capability, is used for precise remote manipulation. The power manipulators so frequently occur the control input saturation that the precise control performances are not achieved due to the windup phenomenon. An advanced bilateral control scheme compensating for the saturation is applied to the teleoperated manipulator system. The validity of the developed system is verified by the grid cutting and fuel transportation tasks from the mockup spent fuel bundle.