• Applied Microscopy
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• v.42 no.2
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• pp.111-114
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• 2012

The scanning electron microscopy is an ideal technique for examining plant surface at high resolution. Most hydrate samples, however, must be fix and dehydrate for observation in the scanning electron microscope. Because the microscopes operate under high vacuum, most specimens, especially biological samples, cannot withstand water removal by the vacuum system without morphological distortion. Cryo-techniques can observe in their original morphology and structure without various artifacts from conventional sample preparation. Rapid cooling is the method of choice for preparing plant samples for scanning electron microscopy in a defined physiological state. As one of cryo-technique, high-pressure freezing allows for fixation of native non-pretreated samples up to $200{\mu}M$ thick and 2 mm wide with minimal or no ice crystal damage for the freezing procedure. In this study, we could design to optimize structural preservation and imaging by comparing cryo-SEM and convention SEM preparation, and observe a fine, well preserved Arabidopsis stem's inner ultrastructure using HPF and cryo-SEM. These results would suggest a useful method of cryo-preparation and cryo-SEM for plant tissues, especially intratubule and vacuole rich structure.

• Journal of Plant Biology
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• v.3 no.1
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• pp.32-38
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• 1960

Since the peculiar virus disease of chinese date tree (Zizyphus jujuba Mill. var. inermis Rehd.) has been noted in South Korea around 1950, 70% to 80% of the economically important trees have been either completely destroyed or infected with the virus, severe damage has been noted, particularly, across the area ranged from middle east to the middle part of Korea, including Seoul area. Yoon-Koock-Byung in 1958 first reported the disease and descirbed it might be caused by a kinds of yellows. But he did not conform in his paper that the disease is pecisely caused by yellows virus. The authors, hereby intend to identify the true cause of the desease of the chinese data tree by studying the external symptoms of the disease and the internal morphological characteristics of the diseaset plant which shows various abnormalities in contrast to the healthy checks. In view of fact that leaves of the infected plants become yellowish in color similar to the peach yellows, aster yellows, it is likely to be identifiable as the common yellows. Furthermore, the abnormal characteristics observed by the authors are as follow: The floral organs such as petals, sepals, stamens, and pistil turn into vegetative leaves, the leaves on heavily infected plant appear as small sized one and also showing as a common witch's broom like symptom. There are also an occuring of numerous advantitious shoots developed from both of stems and roots. The amount of photosynthetic starch grains increases in parenchymatous cells, necrosis takes place in mesophyll, Particularly, Palisade Parenchyma in the leaves of infected plants are distinguished in contrast to the healthy checks. From the symptoms and the present experimetns described above, the authors are believed that the disease of chinese data tree is not caused by the yellows. It appears the disease is rather similar to the symptoms of sandal spike virus which was noted in India early in this centry. But the host plant of standal disease, Santalum albun L. and the insect vector, Jassus indicus Wal., have never been reported in Korean flora and the founa. The termperature and the otehr environmental factors is quite different Korea and India. Thus the authors believe that the peculiar disease must be an endemic new virus origin in Korea and must be called as "shoot cluster disease of chinese date tree."

• Journal of Conservation Science
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• v.30 no.3
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• pp.299-306
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• 2014

The possibility of a low-temperature argon plasma treatment as a mean of restoration technology for contaminated invaluable archive materials and artefacts, and evidencing documents was investigated along with an oxygen plasma treatment for comparison. For this purpose, the degree of color changes, ${\Delta}E^*ab$, and surface morphological changes due to plasma treatments as an evaluation of removal performance of artificial contaminants such as brilliant green dye and carbon deposit on cellulose acetate and plain paper as matrices, respectively, were measured and analyzed using a spectrophotometer and a field emission scanning electron microscope. Compared to the argon plasma treatment with sputtering characteristic, that of the oxygen plasma with characteristic of an oxidation reaction has shown superior results in removing the contaminants; the oxygen plasma has proven to damage the matrices significantly due to its oxidative characteristic, and post-plasma reactions has anticipated to be also detrimental to the surfaces, whereas, the problems caused by the counterpart has resulted in being negligible and rather has thought to be an appropriate mean for delicate restoration and/or removal operations of contaminants.

• Journal of Astronomy and Space Sciences
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• v.34 no.4
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• pp.315-330
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• 2017

Halo coronal mass ejections (CMEs) originating from solar activities give rise to geomagnetic storms when they reach the Earth. Variations in the geomagnetic field during a geomagnetic storm can damage satellites, communication systems, electrical power grids, and power systems, and induce currents. Therefore, automated techniques for detecting and analyzing halo CMEs have been eliciting increasing attention for the monitoring and prediction of the space weather environment. In this study, we developed an algorithm to sense and detect halo CMEs using large angle and spectrometric coronagraph (LASCO) C3 coronagraph images from the solar and heliospheric observatory (SOHO) satellite. In addition, we developed an image processing technique to derive the morphological and dynamical characteristics of halo CMEs, namely, the source location, width, actual CME speed, and arrival time at a 21.5 solar radius. The proposed halo CME automatic analysis model was validated using a model of the past three halo CME events. As a result, a solar event that occurred at 03:38 UT on Mar. 23, 2014 was predicted to arrive at Earth at 23:00 UT on Mar. 25, whereas the actual arrival time was at 04:30 UT on Mar. 26, which is a difference of 5 hr and 30 min. In addition, a solar event that occurred at 12:55 UT on Apr. 18, 2014 was estimated to arrive at Earth at 16:00 UT on Apr. 20, which is 4 hr ahead of the actual arrival time of 20:00 UT on the same day. However, the estimation error was reduced significantly compared to the ENLIL model. As a further study, the model will be applied to many more events for validation and testing, and after such tests are completed, on-line service will be provided at the Korean Space Weather Center to detect halo CMEs and derive the model parameters.

• 한국지형공간정보학회:학술대회논문집
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• 2002.11a
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• pp.117-122
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• 2002

Change detection is a useful technology that can be applied to various fields, taking temporal change information with the comparison and analysis among multi-temporal satellite images. Especially, change detection that utilizes high-resolution satellite imagery can be implemented to extract useful change information for many purposes, such as the environmental inspection, the circumstantial analysis of disaster damage, the inspection of illegal building, and the military use, which cannot be achieved by lower middle-resolution satellite imagery. However, because of the special characteristics that result from high-resolution satellite imagery, it cannot use a pixel-based method that is used for low-resolution satellite imagery. Therefore, it must be used a feature-based algorithm based on the geographical and morphological feature. This paper presents the system that builds the change map by digitizing the boundary of the changed object. In this system, we can make the change map using manual or semi-automatic digitizing through the user interface implemented with a floating window that enables to detect the sign of the change, such as the construction or dismantlement, more efficiently.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.1
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• pp.153-158
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• 2016

A detection algorithm of fallen pear bags caused by natural disaster like heavy rain, typhoon, hurricane, etc. is presented in this paper. The algorithm is developed for the gray pear bags with printed characters which are widely used at pear farms at Sangju and Naju producing large quantity of pears for export. It sets a region of interest (ROI) at first and then eliminates the regions having chromatic color in ROI. Morphological operation and prior information are used to eliminate small noises and several unusual regions and finally the regions of fallen pear bags are remained. The remained regions are analyzed and counted to estimate the scale of damage. Test images are consisted of the images taken at pear farms of Sangju and Naju at 2014. Experimental result shows that the detection rate of pear bags is more than 90% and also the proposed system can be implemented in real-time using hand-held devices because of its simple and parallel architecture.

• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.113-118
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• 2003

We recently extracted lignans such as matairesinol and 2-hydroxyarctigenin from safflower seeds and found that they exhibit a potent cytotoxic effect on human promyleocytic leukemia HL-60 cells. In this study, we investigated whether mechanisms of the matairesinol-induced cell death are associated with the programmed cell death, apoptosis. Matairesinol dose-dependently reduced viability of HL-60 cells with an IC/sun 50/ value of 60 $\mu$M. Staining of cells with Hoechst 33342 revealed distinct morphological features of apoptosis, such as the nuclei broken into chromatin containing fragments of various sizes in the cells exposed to 100 $\mu$M matairesinol for 24 hr. Agarose gel electrophoresis of DNA from the cells treated with matairesinol showed internucleosomal DNA degradation into oligonucleosomal sizes. DNA ladder like patterns were easily detected after treatment with matairesinol concentrations ranging from 10 to 100 $\mu$M after 24 hr. In cells treated with 100 $\mu$M matairesinol for differing time periods, the DNA ladder was detectable from 6 hr onward. A time course histogram of the DNA content analyzed by flow cytometry revealed a rapid increase in subdiploid cells and a concomitant decrease in diploid cells exposed to 100 $\mu$M matairesinol. These results indicate that matairesinol-induced HL-60 cell death was due to the DNA damage and apoptosis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.6
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• pp.1368-1378
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• 2009

Unfolded protein response (UPR) is an important genomic response to endoplasmic reticulum (ER) stress. The ER response is characterized by changes in specific proteins, induction of ER chaperones and degradation of misfolded proteins. Also, the pathogenesis of several diseases like Alzheimer's disease, neuronal degenerative diseases, and diabetes reveal the role of ER stress as one of the causative mechanisms. Borneolum has been used for neuronal disease in oriental medicine. In the present study, the protective effect of borneolum on thapsigargin-induced apoptosis in rat C6 glial cells. Treatment with C6 glial cells with 5 uM thapsigargin caused the loss of cell viability, and morphological change, which was associated with the elevation of intracellular $Ca^{++}$ level, the increase in Grp78 and CHOP and cleavage of pro-caspase 12 Furthermore, thapsigargin induced Grp98, XBP1, and ATF4 protein expression in C6 glial cells. Borneolum reduced thapsigargin-induced apoptosis through ER pathways. In the ER pathway, borneolum attenuated thapsigargin-induced elevations in Grp78, CHOP, ATF4, and XBP1 as well as reductions in pro-caspase 12 levels. Also, our data showed that borneolum protected thapsigargin-induced cytotoxicity in astrocytes from rat (P3) brain. Taken together, our data suggest that borneolum is neuroprotective against thapsigargin-induced ER stress in C6 glial cells and astrocytes. Accordingly, borneolum may be therapeutically useful for the treatment of thapsigargin-induced apoptosis in central nervous system.

• Weed & Turfgrass Science
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• v.1 no.4
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• pp.76-79
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• 2012

This study provides basic information on morphological characteristics of zoysia mite, Aceria zoysiae and symptom in zoysiagrass for turfgrass management in golf courses. Zoysiagrass mite distributed from Pocheon, Gyeonggii province to Jinju, Gyeongnam province and damaged turfgrasses from spring to fall. Damaged leaf by zoysiagrass mite was rolled unidirectionally and mite damaged leaves in the inside of rolled part. Leaves was turned to yellow and damaged area formed irregular yellow patch.

• Biomolecules & Therapeutics
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• v.11 no.4
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• pp.214-223
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• 2003

Methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA) have become popular recreational drugs of abuse in many countries. Although the neurotoxic damage caused by METH and MDMA is characterized by degeneration of the dopaminergic and serotonergic systems in brain, the molecular and cellular mechanisms remain to be clarified. Therefore, the purposes of this study were to confirm the capability of METH and MDMA to induce apoptosis and to clarify the action of its molecular mechanism by using serotonergic JAR cells and dopaminergic SK-N-SH cells. METH and MDMA were dose-dependently cytotoxic to human serotonergic JAR cells and dopaminergic SK-N-SH cells. The morphological change of apoptosis was found in Giemsa staining and TUNEL and further verified in DNA fragmentation analysis. Immunoblotting analysis revealed proteolytic cleavage of caspase-3 and -9 and change of bcl-2 and bax proteins. These results suggest that METH and MDMA may induce caspase-dependent apoptosis via the mitochondrial cell death pathway and METH and MDMA-induced neurotoxicity may happen to broadly and independently of both dopaminergic and serotonergic systems.