• Molecules and Cells
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• v.26 no.2
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• pp.113-120
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• 2008

Laser light microscopy enables observation of various simultaneously occurring events in living cells. This capability is important for monitoring the spatiotemporal patterns of the molecular interactions underlying such events. Two-photon excited fluorescence microscopy (two-photon microscopy), a technology based on multiphoton excitation, is one of the most promising candidates for such imaging. The advantages of two-photon microscopy have spurred wider adoption of the method, especially in neurological studies. Multicolor excitation capability, one advantage of two-photon microscopy, has enabled the quantification of spatiotemporal patterns of $[Ca^{2+}]_i$ and single episodes of fusion pore openings during exocytosis. In pancreatic acinar cells, we have successfully demonstrated the existence of "sequential compound exocytosis" for the first time, a process which has subsequently been identified in a wide variety of secretory cells including exocrine, endocrine and blood cells. Our newly developed method, the two-photon extracellular polar-tracer imaging-based quantification (TEPIQ) method, can be used for determining fusion pores and the diameters of vesicles smaller than the diffraction-limited resolution. Furthermore, two-photon microscopy has the demonstrated capability of obtaining cross-sectional images from deep layers within nearly intact tissue samples over long observation times with excellent spatial resolution. Recently, we have successfully observed a neuron located deeper than 0.9 mm from the brain cortex surface in an anesthetized mouse. This microscopy also enables the monitoring of long-term changes in neural or glial cells in a living mouse. This minireview describes both the current and anticipated capabilities of two-photon microscopy, based on a discussion of previous publications and recently obtained data.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.05a
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• pp.149-149
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• 2003

To understand environmental paths of the transport and accumulation of endocrine disrupting chemicals (EDCs), a single cell multimedia fate model has been constructed and evaluated. The EDCs of concern were PAHs, Organochlorine Pesticides (OCPs), PCBs, Alkyl phenols, and phthalates. An evaluation model was designed for the multimedia distribution, including air, water, soil, sediment and vegetation. This model was verified using reported values and via monitoring data. Based on collected data, the distribution trends of EDCs with respect to environmental media were analyzed. Those results have applied to the model for the prediction of the spatial and temporal distribution of EDCs in Seoul. Especially, phenol compound, phthalates, PAHs, PCBs and organochlorine pesticides were estimated and the model was verified. This model was successfully conducted to environmental media, such as air (vapor and suspended particles), soils (forest soil, bare soil, and cement-concrete covered soil), water (dissolved and suspended solids), sediment, trees (deciduous and coniferous). The discrepancies between the model prediction and the measured data are approximately within or near a factor of 10 for the PAHs of three rings through that of six rings, implying that multimedia distribution of the PAHs could be predicted with a factor of 10. Concerning about the air equilibrium may be assumed, a fugacity at steady state is similar in all environmental media. Considering the uncertainties of this model, the use of equilibrium models may be sufficient for assessing chemical fates. In this study, a suggestion was made that modeling and estimation of chemicals in environmental multimedia be rigorously evaluated using the measured flux data. In addition, these data should be obtained, for example, from the precise and standardized inventory of the target chemicals. The model (EDC Seoul) will be refined in an on-going research effort and will be used to support decision-making concerning the management of EDCs.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.145-145
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• 2011

Light-emitting diodes (LEDs) based on III-nitrides compound semiconductors have achieved a high performance device available for display and illumination sector. However, the conventional c-plane oriented LED structures are still showing several problems given by the quantum confined Stark effect (QCSE) due to the effects of strong piezoelectric and spontaneous polarizations. The QCSE results in spatial separation of electron and hole wavefunctions in quantum wells, thereby decreasing the internal quantum efficiency and red-shifting the emission wavelength. Due to demands for improvement of device performance, nonpolar structure has been attracting attentions, since the quantum wells grown on nonpolar templates are free from the QCSE. However, current device performance for nonpolar LEDs is still lower than those for conventional LEDs. In this study, we discuss the potential possibilities of nonpolar LEDs for commercialization. In this study, we characterized current-light output power relation of the a-plane InGaN/GaN LEDs structures with the variation of quantum well structures. On-wafer electroluminescence measurements were performed with short pulse (10 us) and low duty factor (1 %) conditions applied for eliminating thermal effects. The well and barrier widths, and indium compositions in quantum well structures were changed to analyze the efficiency droop phenomenon.

• Journal of Pharmacopuncture
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• v.20 no.1
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• pp.10-17
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• 2017

Objectives: Boswellic acid (BA), a compound isolated from the gum-resin of Boswellia carterii, is a pentacyclic terpenoid that is active against many inflammatory diseases, including cancer, arthritis, chronic colitis, ulcerative colitis, Crohn's disease, and memory impairment, but the mechanism is poorly understood. This study investigated the effects of boswellic acid on spatial learning and memory impairment induced by trimethyltin (TMT) in Wistar rats. Methods: Forty male Wistar rats were randomly divided into 5 groups: Normal group, TMT-administrated rats (8.0 mg/kg, Intraperitoneally, i.p.) and TMT + BA (40, 80 and 160 mg/kg, i.p.)-administrated rats. BA was used daily for 21 days. To evaluate the cognitive improving of BA, we performed the Morris water maze test. Moreover, to investigate the neuroprotective effect of BA, we determined the acetylcholinesterase (AchE) activity, the malondialdehyde (MDA) level as a marker of lipid peroxidation, and the glutathione (GSH) content in the cerebral cortex. Results: Treatment with TMT impaired learning and memory, and treatment with BA at a dose of 160 mg/kg produced a significant improvement in learning and memory abilities in the water maze tasks. Consistent with behavioral data, the activity of AChE was significantly increased in the TMT-injected rats compared to the control group (P < 0.01) whereas all groups treated with BA presented a more significant inhibitory effect against AChE than the TMT-injected animals. In addition, TMT reduced the GSH content and increased the MDA level in the cerebral cortex as compared to the control group) P < 0.01). On the other hand, treatment with BA at 160 mg/kg slightly increased the GSH content and reduced the MDA level in comparison to the TMT-administered group (P < 0.01). Conclusion: The above results suggest that the effect of BA in improving the cognitive function may be mediated through its antioxidant activity.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.235-238
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• 1995

In this paper, we propose an effective coding method of the angiography by using the scalable structure in the frequency domain for MPACS(Medical Picture Archiving and Communication System). We employed the subband decomposition method and MPEG-2 system which is the international standard coding method of the general moving picture. After the subband decomposition is applied to split an input image into 4 bands in the spatial frequency domain, the motion compensated DPCM coding method of MPEG-2 is carried out for each subband. As a result, an easily controllable coding Structure is accomplished by composing the compound hit stream for each subband group. Follows are the simulation results of the proposed sheme for the angiography. A scalable structure which can be easily controlled for a loss of transmission or the band limit can be accomplisbed in the MPEG-2 stucture by the subband decomposition minimizing the side information. And by reducing the search area of the motion vector between -4 and 3, the processing speed of a codec is enhanced by more than two times without a loss of the picture quality compare with the conventional DCT coefficients decompositon method. And the processing speed is considerably improved in the case of the parallel construction of each subband in the hardware.

• Journal of Environmental Science International
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• v.20 no.11
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• pp.1465-1481
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• 2011

The accuracy of ozone sensitivity coefficients estimated with HDDM (High-order Decoupled Direct Method) can vary depending on the $NO_x$ (Nitrogen Oxides) and VOC (Volatile Organic Compound) conditions. In order to evaluate the applicability of HDDM over the Seoul Metropolitan Area (SMA) during a high ozone episode in 2007 June, we compare BFM (Brute Force Method) and HDDM in terms of the $1^{st}$-order ozone sensitivity coefficient to explain ozone change in response to changes in NOx and VOC emissions, and the $2^{nd}$-order ozone sensitivity coefficient to represent nonlinear response of ozone to the emission changes. BFM and HDDM estimate comparable ozone sensitivity coefficients, exhibiting similar spatial and temporal variations over the SMAduring the episode. NME (Normalized Mean Error) between BFM and HDDM for the episode average $1^{st}$- and $2^{nd}$-order ozone sensitivity coefficients to NOx and VOC emissions are less than 3% and 9%, respectively. For the daily comparison, NME for the $1^{st}$- and $2^{nd}$-order ozone sensitivity coefficients are less than 4% ($R^2$ > 0.96) and 15% ($R^2$ > 0.90), respectively. Under the emission conditions used in this study, two methods show negative episode average $1^{st}$-order ozone sensitivity coefficient to $NO_x$ emissions over the core SMA. The $2^{nd}$-order ozone sensitivity coefficient to $NO_x$ emissions leads ozone to respond muchnonlinear to the reduction in $NO_x$ emissions over Seoul. Nonlinear ozone response to reduction in VOC emissions is mitigated due to the $2^{nd}$-order ozone sensitivity coefficient which is much smaller than the $1^{st}$-order ozone sensitivity coefficient to the emissions in the magnitude.

• Nutrition Research and Practice
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• v.9 no.5
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• pp.480-488
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• 2015

BACKGROUND/OBJECTIVES: Alzheimer's disease (AD) is characterized by deficits in memory and cognitive functions. The accumulation of amyloid beta peptide ($A{\beta}$) and oxidative stress in the brain are the most common causes of AD. MATERIALS/METHODS: Caffeic acid (CA) is an active phenolic compound that has a variety of pharmacological actions. We studied the protective abilities of CA in an $A{\beta}_{25-35}$-injected AD mouse model. CA was administered at an oral dose of 10 or 50 mg/kg/day for 2 weeks. Behavioral tests including T-maze, object recognition, and Morris water maze were carried out to assess cognitive abilities. In addition, lipid peroxidation and nitric oxide (NO) production in the brain were measured to investigate the protective effect of CA in oxidative stress. RESULTS: In the T-maze and object recognition tests, novel route awareness and novel object recognition were improved by oral administration of CA compared with the $A{\beta}_{25-35}$-injected control group. These results indicate that administration of CA improved spatial cognitive and memory functions. The Morris water maze test showed that memory function was enhanced by administration of CA. In addition, CA inhibited lipid peroxidation and NO formation in the liver, kidney, and brain compared with the $A{\beta}_{25-35}$-injected control group. In particular, CA 50 mg/kg/day showed the stronger protective effect from cognitive impairment than CA 10 mg/kg/day. CONCLUSIONS: The present results suggest that CA improves $A{\beta}_{25-35}$-induced memory deficits and cognitive impairment through inhibition of lipid peroxidation and NO production.

• Journal of the Korea Institute of Building Construction
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• v.19 no.4
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• pp.299-306
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• 2019

In general, repair mortar is used to rehabilitate underground communities, but difficulties are encountered in the execution of long-term construction due to spatial co-operatives. In this study, the engineering properties of repair mortar according to the curing condition and accelerator type were reviewed. The results showed that the aluminate, alkali-free and calcium-aluminate precipitates in the water curing conditions showed higher compressive strength at the beginning of age than mortar specimens under air curing conditions, and increased. Especially in CA and AF test specimen with cement mineral quick setting, a large amount of ettringite products were observed compared with AL, thus reducing the pore volume and increasing the strength of the compound by micro-filling effect were found.

• Journal of Environmental Science International
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• v.30 no.2
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• pp.109-118
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• 2021

Due to changes such as those stemming from the onset of the fourth industrial revolution, it is expected that industrial complexes will transform from being spacious structures into smaller, integrated complexes. Green parks, which are also a type of infrastructure within industrial complexes, also require planned direction suited to the changing environment. The planned directions of green parks in new industrial complexes were examined and surveys were conducted on industrial complex workers. Preferred functional arrangement, importance, and satisfaction levels of green ratios, preference of compound facilities linked to parks, appropriate dimensional greening methods were all surveyed across 1,035 businesses. Results of the survey exhibited that there was high awareness on the importance of building green areas, but it was found that current greenery levels were insufficient. There was a high rate of responses indicated that dimensional greening is required in building-type industrial spaces, and preferences for rooftop greenery, stair-type greenery, and atrium greenery were also high. There were many opinions that it is necessary to integrate cultural facilities, exhibition and educational facilities, commercial facilities, parking lots in parks. Furthermore, it was found that it is necessary to provide pathways for bikes and pedestrians, rather than those for vehicles, and to connect them with the green parks. This study stopped short of exploring the directions for which green parks should aim in new industrial complexes with changes in the industrial environment. In the future, more concrete plans on green park planning techniques according to the spatial characteristics and structures of new industrial complexes will be necessary.

• Journal of Ginseng Research
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• v.24 no.1
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• pp.8-17
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• 2000

Estrogen can influence on the expression of behaviors not associated directly with reproduction, including learning and memory. Recently estrogen has received considerable attention for its effects on neuroprotection and neural circuits in brain areas associated with cognition. Although estrogen replacement therapy may be helpful to postmenopausal women, it also results in a number of harmful side effects. Ginseng also has steroidal qualities and contains several ginsenoside components which have similar backbone structure to estrogen. The objectives of this experiment were 1) to examine the effects of estrogen and 2) to investigate the effects of ginsenosides as estrogenic agent on learning and memory using the Morris water maze, a traditional experimental task for spatial memory. In the experiments designed here, ovariectomized mice were implanted subcutaneously with Sila, itic capsules containing 17${\beta}$-estradiol (100∼250 $\mu\textrm{g}$/$m\ell$), panaxadiol (PD) and panaxatriol (PT) saponins (15∼100 $\mu\textrm{g}$/$m\ell$) diluted with sesame oil. In the first set of experiment, the effects of estradiol on learning and memory during the Morris water maze was examined. When estradiol was delivered via Silastic capsules following training improved spatial memory performance in ovariectomized female mice. In the second set of experiment, three different PD and PT saponin concentrations were delivered via Silastic implants to ovariectomized female mice and their effects were compared with estrogenic effects. Results of three separate experiments demonstrated that estradiol, PD and PT administrated by Silastic implants for 2 weeks prior to water maze training significantly improved spatial memory performance compared to ovariectomized (OVX) mice, as indicated by lower escape latency over trial. The positive effect of estradiol suggests that estrogen can affect performance on learning and memory. In addition, the positive effect of PD and PT saponins suggest that ginsenosides have an estrogen-like effects in mediating learning and memory related behavior action.