• The korean journal of orthodontics
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• v.31 no.5 s.88
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• pp.525-534
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• 2001

Bone remodeling in response to force requires coordinated actions of osteoblasts, osteoclasts, osteocytes, and periodontal ligament cells. Coordination among these cells may be mediated, in part, by cell-to-cell communication via gap junctions. This study was designed to evaluate the expression of gap junction, connection 43 In periodontal tissue during the experimental movement of rat's incisors, by LSAB(labelled streptavidine biotin) immunohistochemical staining for connexin 43. Twenty seven Sprague-Dawley rats were divided into a control group(3 rats), and 6 experimental groups(24 rats) where 75g of force was applied from helical springs across the maxillary incisors. Rats of experimental groups were sacrificed at 12 hours, 1, 4, 7, 14 and 28 days after force application, respectively. And the tissues of a control group and experimental groups were studied immunohistochemically. The results were as follows : 1. In control group, the expression of connexin 43 was rare in gingiva, dentin, cementum, periodontal ligament, and bone cells. 2. In experimental group, the expression of connexin 43 was increased in pulp, periodontal ligament, osteoblasts, and osteoclasts, comparing to that in control. And it was rare in gingiva, dentin, and odontoblasts regardless of the duration of force application, which was not different from that of control group. 3. The expression of connexin 43 in pulp of experimental group began to increase in 4-day after force application and got to the highest degree at 7-day. And it decreased after 14-day to be similar to that of control group at 28-day. 4. The expression of connexin 43 in periodontal ligament was noted in small capillaries adjacent to alveolar bone, showing higher intensity of immunolabelling after 4-day And it was stronger in the pressure side than in tension side of periodontal ligament. After 7-day, decrease in connexin 43 expression was observed. 5. The expression of connexin 43 in alveolar bone began to increase 1-day, reached to the highest degree at 4-day, and decreased at 7-day. And the expression in osteoclasts was more than that in osteoblasts or osteocyte at 7-day.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.85-95
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• 2001

The purpose of this study was to evaluate the material for fixed type retainer, allowing physiologic tooth movement. and proper remodeling or periodontal tissue during retention period. The Present study was Performed to observe the histologic changes of periodontal tissue after application of different types of fixed type retainer after orthodontic tooth movement in young adult dogs. For this study, 4 young adult dogs were used as a experimental animal and experimental group was divided into three groups : experimental group 1 contained right side maxillayy third incisors and canines, experimental group 2 contained contralateral teeth of same animals, and control group contained mandibular premolars. And each dogs were applied the 4 different types of fixed type retainer to experimental group 1. The experimental teeth were ligated on the Sentalloy closed coil $spring^{\circledR}$(Tomy Co., Japan) from maxillary third incisors and canines and applied orthodontic force at initial 200gm-forced during 1 week. All the experimental animals were sacrificed on the 3rd week after the orthodontic teeth movement and then the specimens were taken, fixed in formalin, embeded in parafin, sectioned $6-8{\mu}m$ in thickness and stained with Hematoxylin-Eosin staining, and Masson's trichrome staining method. Examined under the light microscopy The following results were observed. 1. There were observed that decreased infiltration of giant tells in pressure side and increased the new bone forming in tension side on the specimen of 6-stranded 0.0195' $Respond^{\circledR}$(G&H Co., U.S.A.) group. Periodontal ligament fibers were much compressed or elongated in 3-stranded 0.018', 0.020' $Dentaflex^{\circledR}$(Dentarum Co., Germany), and Superbond $C&B^{\circledR}$(Sun Medical Co., Japan) groups. 2. In experimental group 1, necrotic bone inside the alveolar bone of pressure side, forming of the sharpey's fiber in osteoid tissue, and remodeling of the periodontal ligament were observed in all animals. 3. In experimental group 2, it was observed that the amount of bone resorption was equal or decreased in pressure side, and increased new bone forming and significantly decreased infiltration of giant cell than the experimental group 1. By this results, it considered that 6-stranded $Respond^{\circledR}$(G&H Co., U.S.A.) wire was the most useful material allowing early periodontal tissue remodeling.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.4
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• pp.85-90
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• 2017

The $TiCl_4$ as a blocking material is adsorbed in the mesoporous $TiO_2$ electron transfer layer(ETL) of the Perovskite solar cell to prevent the direct contact between the FTO electrode and the photoactive layer(AL), and facilitate the movement of the electrons between $TiO_2:TiCl_4$ ETL and Perovskite AL to improve the photoelectric conversion efficiency(PCE). The structure of the perovskite solar cell is FTO/$TiO_2:TiCl_4$/Perovskite($CH_3NH_3PbI_3$)/spiro-OMeTAD/Ag. It was investigated that the dipping time of the $TiO_2$ into $TiCl_4$ aqueous solution affects on the photoelectric characteristics of the device. By the dipping for 30 minutes, the PCE of the perovskite solar cell with the $TiO_2:TiCl_4$ ETL was the highest 10.46%, which is 27% higher than the cell with $TiO_2$ ETL. From SEM, EDS, and XRD characterization on the $TiO_2:TiCl_4$ ETL and the perovskite AL, it was measured that the decrease of the porosity of the $TiO_2$ layer, the detection of the Cl component by the $TiCl_4$ adsorption, the cube-type morphology of perovskite AL, and shift of the $PbI_2$ peak of the perovskite AL. From these results, it was confirmed that the $TiO_2:TiCl_4$ ETL and the perovskite AL were formed.

• Journal of Life Science
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• v.31 no.9
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• pp.787-795
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• 2021

Eupatorium chinensis var. simplicifolium (EUC) has anti-inflammatory and antioxidant effects. Young sprouts of EUC have been used as food for a long time, and the whole EUC plant has been used as an herbal remedy in oriental medicine. Arteriosclerosis, or chronic inflammation in arterial vessels, is a cardiovascular disease and is involved in various disorders. Cardiovascular diseases such as restenosis and neuropathic hyperplasia are mainly caused by abnormal growth and movement due to multiple growth factors in vascular smooth muscle cells (VSMCs). Platelet-derived growth factor (PDGF) is a mitogen released from damaged vessel walls and is involved in the proliferation and migration of VSMCs. To determine the effects of EUC on the abnormal proliferation and migration of VSMCs, the present study investigated intracellular signaling pathways in PDGF-BB-induced VSMCs treated with and without EUC. Pretreating PDGF-BB-induced VSMCs with EUC tended to effectively decrease cell proliferation and migration. Subsequently, the intracellular growth-related signaling pathways of AKT, phospholipase C gamma (PLC-γ), and mitogen-activated protein kinase (MAPK) were investigated using western blotting to confirm inhibited phosphorylation. Furthermore, flow cytometry data showed that EUC blocked the cell cycle of VSMCs. These results suggest that EUC can inhibit the proliferation and migration of VSMCs by controlling the cell cycle and growth factor receptors. Furthermore, this indicates that EUC can be used as a preventative against cardiovascular disease resulting from abnormal proliferation and migration of VSMCs.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.10-14
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• 1978

There are relatively many reports have been issued on he active movement of cuticle of larva. which tend to protect their body, however, only a few reports have been disclosed on the cuticle of pupal body except the small portion of rectangle which shown tortoise-shell shape. In this connection, many portion of the external structure of pupal cuticle has been studied and the following. results were found: 1) No. spot of rectangle which is sculptured in the surface of cuticle that born by branching. out of the development of cell in imaginal bud of antenna and head were found. However, in the compound eye of net shaped sculpture was found in the (equation omitted) shaped parts which holding. the diameter of about 8u and the surrounding area has the small bump and the one is dark brown coloured comparing with shape. 2) The sculpture shape of thorax is a little different than in the head. However, (equation omitted) portion is varies from the segment to segment. In general, it is not very clear than the compound eye in the head, the dark brown bump shape is slowly fade a from the prothorax, mesothorax to metathorax. 3) The surface of intersegment membrane is colourless or slightly yellow, and the entire surface has stripped marking with thine lines. 4) In the abdominal segment, there are many and small sculptures in net shape around the (equation omitted) shape portions. 5) The size of sculpture in (equation omitted) portion of abdomen is smaller than one in thorax, and in the same segment, the dorsal is smaller than abdomen and the rear portion of the segment is larger than the front of segment. 6) After the 7th abdominal segment, no intersegmental membrane is found and the cuticle of the external structure is the same as external structure of the segment. 7) The seta is not found in head, compound eye, antenna and wing which portions were subdivided by development of imagined bud of the cell, no seta is found in cuticle of the segment in the general cell of the larva stage and also in the dorsal and intersegmental membrane.

• Journal of Acupuncture Research
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• v.17 no.2
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• pp.187-208
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• 2000

By the activation of ovary hormone, many morphological changes occur in the epithelial cell lines and muscle cells in rat uterus. These two cells in uterus are important to the implantation of embryo, maintaining pregnancy and starting parturition. One important change associated with the morphological change of these two cells in uterus is the change on prostaglandin(PG) metabolism. Its presence and synthesis in endometriurn and myometrium in uterus affects estrous cycle and the start of embryo implantation in uterus. It also performs as an important modulator in parturition. So the abnormally weak expression of PG causes difficulty during labor and over-expression causes pre-term labor. PG biosynthesis starts from either free or liberated arachidonic acids from membrane phospholipid by phospholipase. Such arachidonic acids are converted into PG catalyzed by Cyclooxygenase. Under normal physiological condition, Cyclooxygenase-1(COX-1) having 602 units of amino acids controls the synthesis of PG. It acts as a local hormone regulating vasomodulation of blood flow, flexible muscle movement, increasing the blood permeability and contributing the protective role in preserving integrity of the stomach lining and Cyclooxygenase-2 (COX-2) is induced by the inflammation, pregnancy and increased its expression until parturition. Lipid metabolite like PG is located in uterine and expression of COX-2 increased with pregnancy. Increased expression of COX proteins in epithelial cells and myometrial cells are told to increase the muscle contractility in uterus but decreased right after the labor in rat. It is a good sign indicating that COX proteins are deeply related to the start of labor. Currently, Several studies report the use of PG and COX-2 inhibitor as medication for controlled abortion or to prevent pre-term labor but they entail various side-effects. Our study proposed to suggest use of acupuncture as an another mediator to control abortion or pre-term labor without causing unnecessary side-effects by those medicines. Two acupuncture sites, LI-4 & SP-6 were selected due to their known efficacy. From the immunohistochemical staining of COX-2, normal expression of COX-2 protein in nonpregnant SD rat's uterus revealed that COX-2 protein was primarily detected in the lumina epithelial lining and in the epithelial cell lining contacting the stromal cells. High resolution optical microscopic scanning revealed distinguishable staining in the myometrial mucosa. LI-4 acupuncture administered nonpregnant rat's uterus showed strong expression for COX-2 in endometrium contacted with lumina epithelial lining of rat uterus and in myometrial mucosa. Stromal cells showed more staining than untreated nonpregnant rat's uterus and stronger staining in stromal cells contacting myometrial layer compared to untreated nonpregnant rat's uterus. SP-6 acupuncture administered nonpregnant rat's uterus showed weak expression for COX-2 in myometrial layers and stromal cells but no staining was visible in lumina epitheliai and glandular epithelial cells. Few stromal cells and myometrial mucosa were positively stained for COX-2. Pregnant SD rat's uterus was also immunostained for COX-2 expression after 18 days of pregnancy. Unlike to untreated nonpregnant rat's uterus, luminal epithelial cells were not positively stained for COX-2 but stronger staining for COX-2 was revealed in stromal cells. LI-4 acupunctured SD rat's uterus had very strong expression of COX-2 in luminal epithelial lining. Few stromal cells showed stronger positive COX-2 staining and myometrial layers also showed more expression than untreated pregnant rat. SP-6 acupuncture administered pregnant SD rat's uterus showed positive expression of COX-2 in epithelial cells of luminal mucosa layer but weaker than that of LI-4 acupuncture treatment's case. However, strong positive staining was revealed in stromal mucosa and myometrial layers. Virgin SD rat's uterus motility index during LI-4 acupuncture was 66.52 % (Prob〉T = 0.0197) compared to its motility before the acupuncture treatment but the motility index was slighdy elevated up to 79.58 % (Prob〉T = 0.1175) after the acupuncture. During the SP-6 acupuncture treatment for 30 minutes, uterus motility index was 90.52 % (Prob〉T = 0.1832) showing lesser decrement but consequently reached similar motility index decreasal to 79.95 % (Prob〉T = 0.0215) after the acupuncture treatment as LI-4 showed. LI-4 acupuncture tend to be a quick treatment to reducing the uterus motility in a virgin rat but eventually both two acupuncture administration created very similar reduction of uterus motility seeing the index after the both acupunctures. The uterus movement monitored during the LI-4 acupuncture administered for 30 minutes, Pregnant SD rat showed decreased motility down to 77.90 % (Prob〉 T = 0.0076) compared to uterus motility before the acupuncture and it continuously decreased down to 71.81 %(Prob〉T = 0.0214) after the removal of needle. The statistical analysis using paired t-test showed significance difference for both two motility indexs at =0.05. SP-6 acupuncture administered to pregnant SD rat also had similar pattern of decreasing uterus motility index down to 74.70 % (Prob〉T = 0.1730) during the initial 30 minutes acupuncture administration and it was continuously lowered to 71.52 % (Prob〉T = 0.0155) after the acupuncture. The paired t-test resuit for SP-6 suggest prompt response of uterus motility index to the SP-6 acupuncture treatment but consequently reached same level of inducing the motility reduction as LI-4 at =0.05 level.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.121-136
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• 2001

This study was performed to analyse the expression of VEGF and it's receptor(VEGFR) in the tension side of the periodontal ligament following orthodontic tooth movement. Upper first molars of Sprague-Dawley rats were moved medially using closed coil spring for 1, 2, 24 hours and 3, 7, 14 days. H&E staining, immunohistochemical staining and in situ hybridization methods were used to analyse the change of the expression of VEGF and VEGFR. The results from this study were as follows : 1. Following tensional force, periodontal ligament showed elongation of fibers, compression and congestion of vessels and regional hemorrhage. These tissue changes were recovered within 3 days of force application. New bone formation was seen after 3 days of force application and continued for the remaining experimental periods. 2. Following tensional force, VEGF and VEGF mRNA expression was increased in the periodontal ligament cells, osteoblasts and cementoblasts. This change was followed by increased vasculature in the periodontal ligament. 3. After 3 days of tensional force, VEGF and VEGF mRNA expression was confined mainly to the osteopaths and the periodontal ligament cells adjacent to the alveolar bone. After 2 weeks of force application, VEGF and VEGF mRNA expression was reduced to the level of control sample. 4. VEGFRs(Flt-1, Flk-1) showed similar expression pattern and it's expression was mainly seen in the endothelial cells and osteoblasts. Following tensional force VEGFR expression was increased in the endothelial cells and osteoblasts. In conclusion, in the tension side of the penodontal ligament, ligament cells, osteoblast and cementoblast showed increased expression of VEGF & VEGF mRNA. It preceded the increase of vasculature and new bone formation. The increased expression of VEGF mRNA in cementoblast may induce periodontal vessels, which distribute mainly the bone side half of periodontal ligament, grow in the direction of tensional force. Increased expression of VEGFR & VEGFR mRNA not only in endothelial cell but in osteoblast, osteocyte and periodontal cells showed VEGF acts not only in paracrine manner but in autocrine one.

• 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.

• Progress in Medical Physics
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• v.22 no.4
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• pp.198-205
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• 2011

Gamma irradiator is widely used for cell, animal experiment, irradiation for blood, dose measurement, and education. Biobeam8000 gamma irradiator (STS Steuerungstechnik &. Strahlenschutz GmbH, Braunschweig, Germany, Cs137, 81.4 TBq) that KIRAMS (Korea Institute of Radiological and Medical Science) has is a irradiation device that enables to be used in large-capacity of 7.5 L and extensive area. Cs-137 source moves range of 24 cm back-and-forth in a regular cycle in beaker for uniform irradiation and a beaker that puts a specimen like existing radiation irradiator such as Gammacell3000 rotates $360^{\circ}$ during irradiation. Precise dose information according to the location of radiation source would be needed because of the movement of radiation source, whereas radiation could be uniformly irradiated in comparison with existing gamma irradiator. In this study, dose distribution of the inside beaker located in Biomeam8000 gamma irradiator was measured using glass dosimeter, and dose evaluation and distribution regarding dose linearity and dose reproducibility were implemented based on measurement results. This aims to show guideline for efficient use of irradiator based on measurement result when doing experiment or radiation exposure.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.1
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• pp.37-46
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• 2016

This study describes the spatio-temporal distributions in phytoplankton community such as species composition, standing crops and dominant species from April to November 2008 in the Uljin Marine Ranching Area (UMRA). A total of 123 species of phytoplankton belonging to 67 genera was identified. In particular, diatoms and dinoflagellates were occupied more than 60.5% and 34.6% of total species, respectively. The annual dominant species were Thalassiosira sp., Pseudo-nitzschia pungens in spring, Leptocylindrus danicus, Guinardia striata in early summer, Cheatoceros cirvisetus, Ch. decipiens in early autumn and Skeletonema costatum -ls (like species), Pn. pungens in autumn. Phytoplankton cell density fluctuated with an annual mean of $48cells{\cdot}mL^{-1}$ between the lowest value of $1.8cells{\cdot}mL^{-1}$ in early autumn and the highest value of $240cells{\cdot}mL^{-1}$ in spring. According to the cluster analysis, the phytoplankton community of the UMRA was characterized by the nutrient supply from land side and water movement as current.