• Applied Chemistry for Engineering
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• v.19 no.3
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• pp.270-276
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• 2008

$N_2$ doped $TiO_2$ nano-sized powder was prepared using a DC arc plasma jet and investigated with XRD, BET, SEM, TEM, and photo-catalytic decomposition. Recently the research interest about the nano-sized $TiO_2$ powder has been increased to improve its photo-catalytic activity for the removal of environmental pollutants. Nitrogen gas, reacting gas, and titanium tetrachloride ($TiCl_4$) were used as the raw materials and injected into the plasma reactor to synthesize the $N_2$ doped $TiO_2$ power. The particle size and XRD peaks of the synthesized powder were analyzed as a function of the flow rate of the nitrogen gas. Also, the characteristics of the photo-catalytic decomposition using the prepared powder were studied. For comparing the photo-catalytic decomposition performance of $TiO_2$ powder with that of $TiO_2$ coating, $TiO_2$ thin films were prepared by the spin coating and the pulsed laser deposition. For the results of the acetaldehyde decomposition, the photo-catalytic activity of $TiO_{2-x}N_x$ powder was higher than that of the pure $TiO_2$ powder in the visible light region. For the methylene blue decomposition, the decomposition efficiency of $TiO_2$ powder was also higher than that of $TiO_2$ film.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.6
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• pp.326-333
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• 2020

Nitrate-nitrite-nitric oxide (NO) pathway is a major alternative source of NO and is essential for NO - dependent physiological functions in body. Food supplements having nitrate/nitrite can improve metabolic syndromes including hypertension through antioxidant activity or vasodilation. The purpose of this study was to observe the effects of fermented garlic (F. garlic) having high concentration of NO2- on changes in blood flow and nitric oxide synthesis in the cerebral cortex of rodents. The generation of nitric oxide detected by a chemi-luminescence detector was higher in F. Garlic compared with NaNO2 solution under artificial gastric juice with pH 2.0. Ether F. garlic or NaNO2 diluted with artificial cerebrospinal fluid was directly applied into around the needle probe of laser Doppler flow meter that was located on epidural surface of the cortex. Direct application of F. garlic resulted in increase of cerebral blood flow detected by a laser Doppler flow meter with a dose-dependent manner. Compared with NaNO2 solution, F. garlic produced changes in cerebral blood flow at lower concentration of NO2-. Pretreatment of methylene blue, a guanylyl cyclase inhibitor prevented upregulation of cerebral blood flow by the treatment of F. garlic. In addition, the application of F. garlic with 250, 500ppm of NO2- caused significantly the production of NO in the cortical tissue but NaNO2 solution with 500ppm of NO2- did not. In summary, these results suggested that F. garlic with high content of NO2- induce increase in cerebral blood flow through nitric oxide-dependent signal pathway.

• Korean Journal of Materials Research
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• v.26 no.6
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• pp.347-352
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• 2016

ZnO with wurtzite structure has a wide band gap of 3.37 eV. Because ZnO has a direct band gap and a large exciton binding energy, it has higher optical efficiency and thermal stability than the GaN material of blue light emitting devices. To fabricate ZnO devices with optical and thermal advantages, n-type and p-type doping are needed. Many research groups have devoted themselves to fabricating stable p-type ZnO. In this study, $As^+$ ion was implanted using an ion implanter to fabricate p-type ZnO. After the ion implant, rapid thermal annealing (RTA) was conducted to activate the arsenic dopants. First, the structural and optical properties of the ZnO thin films were investigated for as-grown, as-implanted, and annealed ZnO using FE-SEM, XRD, and PL, respectively. Then, the structural, optical, and electrical properties of the ZnO thin films, depending on the As ion dose variation and the RTA temperatures, were analyzed using the same methods. In our experiment, p-type ZnO thin films with a hole concentration of $1.263{\times}10^{18}cm^{-3}$ were obtained when the dose of $5{\times}10^{14}$ As $ions/cm^2$ was implanted and the RTA was conducted at $850^{\circ}C$ for 1 min.

• Progress in Medical Physics
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• v.6 no.2
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• pp.61-70
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• 1995

The picosecond time resolved fluorescence spectra of Hematoporphyrin Derivative (HPD) in both solutions and cancer cell are measured by a time correlated single photon counting system with a synchronously mode locked dye laser. Two exoponential decay components in the fluorescence spectra were observed. The slow decay(6.3 ㎱)and the fast one(350 ㎰)are attributed to be originated from monomers and dimers, respectively. The absorption and fluorescence measurements in steady state also showed the presence of a monomeric and dimeric forms of HPD molecules. The monomer lifetime in the cancer cell was measured to be longer than that in solution, which was expected from the blue shift and narrowing of the absorption spectra for HPD-treated in vitro. The relative amplitude of the fast component was found to be enhanced in cancer cell, strongly indicating the higher affinity of the dimer for the cancer cell.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.3
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• pp.257-263
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• 2009

This study aimed to investigate whether selective serotonin reuptake inhibitors (SSRIs) attenuate brain injury and facilitate recovery following photothrombotic cortical ischemia in mice. Male ICR mice were anesthetized and systemically administered Rose Bengal. Permanent focal ischemia was induced in the medial frontal and somatosensory cortices by irradiating the skull with cold light laser. The animals were treated with fluoxetine or sertraline once a day for 14 d starting 1 h after ischemic insult. Treatment with fluoxetine and sertraline significantly reduced the infarct size. The Evans blue extravasation indices of the fluoxetine- and sertraline-treated groups were significantly lower than that of the vehicle group. Treatment with fluoxetine and sertraline shifted the lower limit of the mean arterial blood pressure for cerebral blood flow autoregulation toward normal, and significantly increased the expression of heme oxygenase-1 (HO-1) and hypoxia-inducible factor-1 ${\alpha}$ (HIF-1 ${\alpha}$) proteins in the ischemic region. These results suggest that SSRIs, such as fluoxetine and sertraline, facilitate recovery following photothrombotic cortical ischemia via enhancement of HO-1 and HIF-1 ${\alpha}$ proteins expression, thereby providing a benefit in therapy of cerebral ischemia.

• Journal of Acupuncture Research
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• v.21 no.1
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• pp.33-50
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• 2004

Objective: The aim of this study was to investigate anti-ischemic effect of LR1 HT8 Reduction in Acupuncture Methods: I designed to investigate whether LR1 HT8 Reduction in Acupuncture affects cerebral hemodynamics [regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure(MABP)] in normal rats and to make manifest whether LR1 HT8 Reduction in Acupuncture is mediated by cyclooxygenase or guanylate cyclase. The changes of rCBF and MABP were determinated by laser-doppler flowmetry(LDF), and the change of PAD was de terminated by video microscope and width analyzer. Results: The results were as follows; 1. LR1 Reduction in Acupuncture was increased rCBF and PAD, but decreased MABP. 2. HT8 Reduction in Acupuncture was significantly increased rCBF, but decreased MABP, and increased PAD. 3. LR1 HT8 Reduction in Acupuncture was significantly increased rCBF, PAD, but decreased MABP after withdrawing of the needle. This results suggest that LR1 HT8 Reduction in Acupuncture increased significantly rCBF by dilating PAD. 4. Pretreatment with indomethacin(1mg/kg, i,v.) was significantly inhibited LR1 HT8 Reduction in Acupuncture induced increase of rCBF and PAD, but increased LR1 HT8 Reduction in Acupuncture induced decrease of MABP after withdrawing of the needle. 5. Pretreatment with methylene blue($10{\mu}g/kg$, i,v.) was decreased LR1 HT8 Reduction in Acupuncture induced increase of rCBF and PAD, but accelerated LR1 HT8 Reduction in Acupuncture induced decrease of MABP. Conclusions: I suggest that LR1 HT8 Reduction in Acupuncture has an anti-ischemic effect through the improvement of cerebral hemodynamics, and the mechanism is mediated by cyclooxygenase.

• Journal of Periodontal and Implant Science
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• v.48 no.3
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• pp.164-173
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• 2018

Purpose: The aim of this study was to evaluate the antimicrobial effect of a newly devised toothbrush with light-emitting diodes (LEDs) on Porphyromonas gingivalis attached to sandblasted and acid-etched titanium surfaces. Methods: The study included a control group, a commercial photodynamic therapy (PDT) group, and 3 test groups (B, BL, and BLE). The disks in the PDT group were placed in methylene blue and then irradiated with a diode laser. The B disks were only brushed, the BL disks were brushed with an LED toothbrush, and the BLE disks were placed into erythrosine and then brushed with an LED toothbrush. After the different treatments, bacteria were detached from the disks and spread on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy was performed to visualize bacterial alterations. Results: The number of viable bacteria in the BLE group was significantly lower than that in the other groups (P<0.05). Scanning electron microscopy showed that bacterial cell walls were intact in the control and B groups, but changed after commercial PDT and LED exposure. Conclusions: The findings suggest that an LED toothbrush with erythrosine treatment was more effective than a commercial PDT kit in reducing the number of P. gingivalis cells attached to surface-modified titanium in vitro.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.3
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• pp.746-750
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• 2003

Cheonghunhwadam-tang have been used in oriental medicine for many centuries as a therapeutic agent of vertigo by wind, fire and phlegm. CHT Gamypang(CTG) was CHT adding Aurantii Fructus(AF). The effects of CTG on the regional cerebral blood f1ow(rCBF) and mean arterial blood pressure(MABP) is not known. The mechanical Study of CTG on the cerebral hemodynamics is not known too. Therefore, purpose of this Study was to investigate effects of CTG on the rCBF and MABP, mechanism of CTG on the cerebral hemodynamics in rats. The changes of rCBF and BP was determinated by Laser-Doppler Flowmetry(LDF). The results were as follows ; CTG extract was significantly decreased rCBF in a dose-dependent, but the change of MABP was not shown. Pretreatment with propranolol(3mg/kg, i.v.) was significantly increased CTG(10 mg/kg, i.v.) induced decrease of rCBF. Pretreatment with indomethacin(3mg/kg, i.v.) and methylene blue(10㎍/kg, i.v.) were increased CTG induced decrease of rCBF too. This results suggest that the mechanism of CTG is mediated by adrenergic β - receptor, guanylate cyclase and cyclooxygenase.

• Applied Microscopy
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• v.25 no.3
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• pp.75-81
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• 1995

The microstructural characterization of ternary $ZnS_{x}Se_{1-x}$(x=0.085) on GaAs(001) substrate grown up to $2{\mu}m\;at\;300^{\circ}C$ by molecular beam epitaxy(MBE) which has a single growth chamber was investigated by high resolution transmission electron microscope (HRTEM) working at 300 kV with point resolution of 0.18nm. The interface in the ZnSSe/GaAs specimen maintains a pseudomorphism with the substrate, but the epilayer has high density of stacking faults and moire fringes. The pits which had formed along <111> direction were found at the interface of ZnSSe/GaAs. The pits were responsible for producing defects in both epilayer and substrate. The wavy interface which has the difference of 15nm in height was found to maintain the pseudomorphism with the substrate and no stacking faults were found around the interface. However there exists faint and fine moire fringes in the epilayer near interface.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1194-1201
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• 2003

Jaeumgenby-tang(JGT) have been used in oriental medicine for many centries as a therapeutic agent of vertigo caused by deficiency of qi(氣) and blood(血). Effect of Aurantii Fructus(AF) take off the phlegm by promoting the circulation of qi, Gastrodae Rhizoma(GR) has effects treating for headarch, vertigo by calming the liver and suppressing hyperactivity of the liver-yang (陽). I investigated whether injection of JGT adding AFㆍGR extract(JTG) affects cerebral hemodynamics [regional cerebral blood f1ow(rCBF), pial arterial diameter(PAD) in cerebral ischemia rats by MCA occlusion method, and I designed to make manifest whether JTG is mediated by adrenergic β-receptor, cyclooxygenase or guanylate cyclase. The changes of rCBF was determinated by laser-doppler flowmetry(LDF), and the changes of PAD was determinated by video microscope and width analyzer. The results were as follows in cerebral ischemic rats; The changes of rCBF and PAD were increased stabilizly by treatment with JTG(10 ㎎/kg, i.v.) during the period of cerebral reperfusion, and pretreatment with propranolol and indomethacin were increased JTG induced increase of rCBF and PAD during the period of cerebral reperfusion. Pretreatment methylene blue was decreased JTG induced increase of rCBF and PAD during the period of cerebral reperfusion. In conclusion, JTG causes a diverse response of rCBF and PAD, and action of JTG is mediated by adrenergic β-receptor and cyclooxygenase. I suggest that JTG has an anti-ischemic effect through the improvement of crebral hemodynamics.