• Journal of Ginseng Research
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• v.13 no.1
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• pp.71-78
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• 1989

The structural changes in the pericarp of Panax ginseng fruit cells are studied during maturation periods. The pericarp can be divided into exocarp, mesocarp and endocarp. The exocarp consists of one layer of epidermal cells which is covered by a thin cuticle and hypodermal cells. A central vacuole and peripheral cytoplasm are observed in the exocarp and mesocarp. Also, irregular wall arrangement are observed during the differentiation. The endocarp is clearly marked off from the others by secondaw wall thickening and lignification. Secretory materials produced by the Golgi complex and rough endoplasmic reticulum vesicles appear to accumulated in the cell wall. These secretory materials are considered major components of the seed coat during the differentiation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.3
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• pp.106-109
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• 2004

In-situ observational works had been done for the investigation of Cochlodinium polykrikoides cell distributions and abundances off the coast of Busan, Jinhae Bay, and Namhae to Tongyong area in the early June, 2004. The surface water of 11 was concentrated by passing through ${\Phi}$ 10 $\mu\textrm{m}$ mesh and cellular morphological characteristics of the species in the sample was observed under light microscope equipped with digital camera on the vessel. C. polykrikoides cells showed highest cell numbers ranging from 60 to 660 cells/1 at Jinhae Bay. Cell counts at offshore area of Busan ranged from 45 to 330 cells/1. However, no cell was found in the water between Namhae and Tongyong. C. polykrikoides found during the cruise had a large bright red and round cellular materials in one cell and two-celled chain of C. polykrikoides. The red material decreased as C. polykrikoides formed long chains through cell divisions.

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.201-207
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• 2019

This study has evaluated whether the method of using the combination of different risk group, according to K-TIRADS classification and K-TIRADS classification in thyroid ultrasonography is useful in a differential diagnosis of benign and malignant nodules. The subject was patients underwent thyroid ultrasonography and retrospective analysis were performed based on the results of fine needle aspiration cytology. A chi-square test was performed for the difference analysis of the score system in K-TIRADS and different risk group according to the benign and malignant of thyroid nodule. The optimized cut off value was determined by the K-TIRADS score and different risk group to predict malignant nodule through ROC curve analysis. In the differential verification result of K-TIRADS and different risk group, according to the classification of benign and malignant nodule group each showed significant difference statistically(p=.001). In the point classification according to K-TIRADS for the prediction of benign and malignant in ROC curve analysis showed AUC 0.786, Cut-off value>2(p=.001), and in the different risk group, it was decided as AUC 0.640, Cut-off value>2(p=.001). When discovering the nodule in thyroid ultrasound, it is considered that the K-TIRADAS which helps in identifying benign and malignant thyroid nodules, it is considered to be helpful in the differential diagnosis of thyroid nodules, than the classification system according to Different risk group, and when applying the classification system according to K-TIRADS, it is considered that it can reduce unnecessary fine needle aspiration cytology and could be helpful in finding the malignant nodules early.

• Progress in Medical Physics
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• v.9 no.2
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• pp.95-104
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• 1998

The dynamic properties of the 3rd-order neuron of the retina was investigated by using conventional intracellular recording techniques. Experiments were performed in the superfused retina-eyecup preparation of the channel catfish, Ictalurus punctatus. The cornea, iris, lens, and vitreous were removed by absorption with Kimwipe tissue under the dissection microscope thereby exposing the retina in a hemi -eyecup. The electrical signal was amplified by electrometer, viewed on oscilloscope. Regular signals from the cells were recorded on a penwriter and stored by data recorder and computer. Full-field, spot or annular light stimuli were generated on a computer monitor and focused onto the retina. Baclofen hyperpolarized the dark membrane potential, suppressed sustained component and enhanced transient component of the ON-sustained cell with a large transient component, but did not affect the surround antagonism of the cell. Baclofen selectively suppressed responses evoked by moving bar light stimuli on the ON-OFF transient cell. The results suggest that transient cells have directional selectivity in the inner retina. These dynamic properties of amacrine and ganglion cells were modulated by baclofen. Therefore, it is presumed that there is baclofen-induced directional selectivity in ON-OFF transient cells in the catfish retina.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.212-217
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• 2007

As a preliminary study for the development of electrical stimulation strategy of artificial retina, we set up a method fur the reconstruction of input intensity variation from retinal ganglion cell(RGC) responses. In order to estimate light intensity variation, we used an optimal linear filter trained from given stimulus intensity variation and multiple single unit spike trains from RGCs. By applying ON/OFF stimulation(ON duration: 2 sec, OFF duration: 5 sec) repetitively, we identified three functional types of ganglion cells according to when they respond to the ON/OFF stimulus actively: ON cell, OFF cell, and ON-OFF cell. Experiments were also performed using a Gaussian random stimulus and a binary random stimulus. The input intensity was updated once every 90 msec(i. e. 11 Hz) to present the stimulus. The result of reconstructing 11 Hz Gaussian and binary random stimulus was not satisfactory and showed low correlation between the original and reconstructed stimulus. In the case of ON/OFF stimulus in which temporal variation is slow, successful reconstruction was achieved and the correlation coefficient was as high as 0.8.

• Applied Microscopy
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• v.39 no.2
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• pp.199-204
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• 2009

In this study, we observed the effects of repeated perms on the morphology of virgin hair of a healthy thirteen year-old girl with scanning electron microscopy. After the first treatment, the outer parts of cuticle cell were broken unevenly and roughly. Cuticle cells were lifted upward making a space. After the third treatment, cuticle cells were lifted off one another and the folded scales showed irregular surface areas. Broken pieces of cells were stuck on the surface and an empty hole was present in the endocuticle of the cytoplasm. We observed that cortex separated from cuticle layer more easilywith repeated treatments.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.547-552
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• 2004

Recently, autologous bone marrow cell transplantation (CTx) for angiogenesis and myogenesis in ischemic myocardium has been extensively investigated to improve heart functions. This study was designed to evaluate the effects of CTx with off-pump coronary artery bypass grafting (OPCAB) in patients who were not feasible for complete revascularization. Material and Method: Four male patients underwent CTx and OPCAB simultaneously. Bone marrow was aspirated from iliac bone. Mean 1.5 ${\times}$ 10$^{9}$ mononuclear cells including mean 6.7 ${\times}$ 10$^{6}$ CD34 + cells and 3.7 ${\times}$ 10$^{6}$ AC133 + cells were obtained and concentrated with 10 cc. These cells were transplanted into non-graftable ischemic myocardium after OPCAB. The heart function of all patients were evaluated using the MIBI scan, echocardiogram and MRI preoperatively. The effects of CTx was evaluated using MIBI scan and echocardiogram at 1 month postoperatively. Result: An average of 2 grafts were bypassed to left anterior descending artery territory. Other territories were transplanted with isolated mononuclear cell. All patients had uncomplicated postoperative course. After 1 month follow up, there were improvement in symptom, ejection fraction (from 49% to 55%) on echocardiogram and myocardial perfusion on MIBI scan in all patients. Conclusion: These preliminary data showed improvement of heart function and myocardial perfusion and also showed the feasibility and safety of combined therapy with OPCAB and CTx in ischemic myocardium. However, the effectiveness of CTx alone cannot be readily assessed. Further randomized, controlled studies are required to evaluate the effectiveness of CTx alone.

• Journal of Life Science
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• v.25 no.8
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• pp.953-959
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• 2015

Optogenetics is the combination of optical and molecular strategies to control designated molecular and cellular activities in living tissues and cells using genetically encoded light-sensitive proteins. It involves the use of light to rapidly gate the membrane channels that allows for ion movement. Optogenetics began with the placing of light-sensitive proteins from green algae inside specific types of brain cells. The cells can then be turned on or off with pulses of blue and yellow light. Using the naturally occurring algal protein Channelrhodopsin-2 (ChR2), a rapidly gated light-sensitive cation channel, the number and frequency of action potentials can be controlled. The ChR2 provides a way to manipulate a single type of neuron while affecting no others, an unprecedented specificity. This technology allows the use of light to alter neural processing at the level of single spikes and synaptic events, yielding a widely applicable tool for neuroscientists and biomedical engineers. An improbable combination of green algae, lasers, gene therapy and fiber optics made it possible to map neural circuits deep inside the brain with a precision that has never been possible before. This will help identify the causes of disorders like depression, anxiety, schizophrenia, addiction, sleep disorder, and autism. Optogenetics could improve upon existing implanted devices that are used to treat Parkinson’s disease, obsessive-compulsive disorder and other ailments with pulses of electricity. An optogenetics device could hit more specific subsets of brain cells than those devices can. Applications of optogenetic tools in nonneuronal cells are on the rise.

• Applied Microscopy
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• v.33 no.3
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• pp.215-222
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• 2003

The ultrastructure of damaged hair shaft from blow-drying at typical temperature $40{\sim}170^{\circ}C$ for daily beautiful face have been investigated by using transmission electron microscope and scanning electron microscope. When we used to hair dryer for a long time in our everyday life, the following morphological alternations were found in hair. First, the partial of scales in outer cuticle were detached simultaneously with separation of intercellular membrane complex of cuticle cells. Then hair broke cuticle off and exposed to cortex. Secondly, the cortical cell in the cortex was fissured into its macrofibril. The melanin granules were scattered between macrofibrils. As a result, I confirmed that blow-drying removed the hair's bonded water and made hard on hair which lost elasticity. After all, hair showed irregular, rough surface and vanished its luster.

• Applied Biological Chemistry
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• v.45 no.2
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• pp.114-118
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• 2002

Phenalamides $A_1{\sim}A_3$ were reisolated as cytotoxic substances from culture broth of Myxococcus stipitatus JW111. The producing strain was isolated from the marine sediment collected off the shore of Geomun Island, Korea. The active principles were extracted from cell mass with acetone and successively purified by silica gel column chromatography, Sephadex LH-20 column chromatography, and finally recycling prep. HPLC. These compounds demonstrated significant cytotoxicity against certain human cancer cells, having $IC_50$ values ranging from 0.23 to 0.50 ${\mu}g/ml$. Moreover, they also inhibited the growth of adriamycin-resistant HCT/ADM human cancer cell line as well as its parent sensitive cell line.