• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.314-315
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• 2008

We have studied a property change of organic light-emitting diodes (OLED)s due to a surface reformation of indium-tin-oxide(ITO) substrate. An ITO is widely used as a transparent electrode in light-emitting diodes, and the OLEDs device performance is sensitive to the surface properties of the ITO. The ITO surface reformation could reduce the Schottky barrier at the ITO/organic interface and increase the adhesion of the organic layer onto the electrode. We have studied the characteristics of OLEDs with a treatment by a wet processing of the ITO substrate. The self-assembled monolayer(SAM) was used for wet processing. The characteristics of OLEDs were improved by SAM treatment of an ITO in this work. The OLEDs with a structure of ITO/TPD(50nm)/$Alq_3$(70nm)/LiF(0.5nm)/Al(100nm) were fabricated, and the surface properties of ITO were investigated by using seneral characterization techniques. Self-assembled monolayer introduced at the anode/organic interface gave an improvement in turn-on voltage, luminance and external quantum efficiency compared to the device without the SAM layer. SAM-treatment time of the ITO substrate was made to be 0/10/15/20/25min. The current efficiency of the device with 15min. treated SAM layer was increased by 3 times and the external quantum efficiency by 2.6 times.

• Journal of Pharmaceutical Investigation
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• v.37 no.1
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• pp.7-13
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• 2007

To produce stable polymer coating layer using the interaction between metal stent and polymer layer, Ahx-HSAB was synthesized by coupling 6-aminoheanoic acid (Ahx) with N-Hydroxy succinimidyl 4-azidobenzonate (HSAB) containing photo reactive group. Then, Ahx-HSAB was applied to self·assembled monolayer (SAM) on $TiO_2$-coated surface, since one end of Ahx-HSAB was carboxyl acid which was known to be able to interact with $TiO_2$ surface. That SAM layer was incubated in 1% polycaprolacton (PCL) solution and photoreacted by ultraviolet light (254 nm) to produce the chemical bond between SAM and polymer layer, followed by PCL polymer coating ({\sim}5\;{\mu}m$) by the method of spray coating. The surface change was investigated by measuring of contact angle of the surface. The contact angle values of stainless steel (SS) surface, $TiO_2$-coated surface, SAM layer by Ahx-HSAB, photoreacted surface with PCL and PCL layer by spray coating were 70.48${\pm}$1.89, 38.57${\pm}$3.31, 60.14${\pm}$2.21, 54.91${\pm}$2.70 and 56.47${\pm}$2.12, respectively. The stability of polymer layers was tested by incubation of PCL-coated plates in 0.1M PBS buffer (pH 7.4, 0.05%, Tween 80) with vigorous shaking (200 rpm). While the poiymer layer prepared by these processes showed the intact surface morphology over 3 days, the polymer layers prepared by spray coating of PCL onto SS plate (control 1) and $TiO_2$-coated SS plate (control 2) were Peeled off in 3 days. Thus, the polymer coating method using SAM and photoreaction seems to be a effective method to obtain the stable polymer layer onto SS surface.

• Journal of Nutrition and Health
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• v.38 no.7
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• pp.495-502
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• 2005

This study was performed to investigate effects of dietary folic acid supplementation on plasma homocysteine levels, thiobarbituric acid reactive substance s (TBARS) level s and liver SAM/SAH ratio in hyperhomocysteinaemia-induced pregnant rats. Forty-two female Sprague-Dawley rats were divided three groups (C: control diet, HFD: $0.3\%$ homocystine and 0 mg folic acid diet, HFS: $0.3\%$ homocystine and 8 mg/kg folic acid diet) according to homocystine and folic acid levels in the diet. They were fed experimental diets for 5 weeks prior to the mating and also during the entire period of pregnancy till gestational day 20. Dietary folic acid supplementation caused a significant decrease in plasma homocysteine levels which had been increased by a homocystine-diet, with a concomitant increase in plasma and liver folate levels. Liver TBARS levels in homocysteine-folic acid-deficient group (HFD) were higher than those in control group. Dietary folic acid supplementation increased hepatic SAM/SAM ratio in homocysteine-folic acid- sopplemetantion group (HFS) when compared to the HFD (p < 0.05). These data suggest that folate depletion and elevated plasma homocysteine may promote oxidative stress in rat livers and influence the remethylation cycle of the homocysteine metabolism detrimentally. In conclusion, dietary folic acid supplementation was found to be effective for lowering plasma homocysteine levels, relieving oxidative stress, and improving the methylation status in the body.

• Journal of the Korean Electrochemical Society
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• v.5 no.4
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• pp.212-215
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• 2002

A superoxide dismutase (SOD)-based superoxide ion $(O_2^-)$ sensor was fabricated by immobilizing SOD on a self-assembled monolayer (SAM) of 3-mercaptopropionic acid (MPA) which was prepared on a gold electrode. The SAM of MPA was found to function as an effective promoter for the electrode reaction of SOD. The amperometric response to $(O_2^-)$ was monitored at 300mV and -100mV vs. Ag/ Agel in 5mM phosphate buffer solution containing $KO_2$. The sensor was proved to have a high sensitivity, selectivity and short response time (<5 s) and negligible interference.

• Journal of Food Hygiene and Safety
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• v.25 no.1
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• pp.10-15
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• 2010

This study was practiced to survey food-borne bacterial aspects of Escherichia coli and Bacilhus cereus etc. from 210 processed seasoned marine products in Garak fishery wholesale market in Seoul, 2009. Distributions of these bacterial isolates were 28 coliforms, 32 Bacillus spp., 71 Staphylococcus spp., 11 Listeria spp, and 10 Enterococcus spp. in 157 dried squids, 23 dried file fishes, and 20 dried pollacks etc. respectively. Results in 16 kinds of antibiotics susceptibility test by disc diffusion method, special multiple drugs resistance patterns were NOR + LVX + CIP + SAM + VA + S + TE + CF, SAM + C + VA, VA + S + TE, and VA + S in 9 E. coli strains, also, AMC + SAM + CF, SAM + CF, and VA + CF in 21 Bacillus cereus strains respectively. On the basis of the results above, many seasoned dried fishes had multiple drugs resistances, conclusively, we suggest limited guideline and special management on use of antibiotics in floating net cages of fishery farms.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.370-381
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• 1998

The effect of herbal medicine on osteoporosis was studied using ovariectomized rats as an animal model of Type I osteoporosis and SAM P6 mice as that of Type II. Each traditiona l boiling water extract of Achyranthis Radix, Psoraleae Radix, Rehmanniae Radix Preparat, Corni Fructus and Mycelia of Ganoderma, and systemic water fraction of Astragali Radix was given 5g(dried herbal weight)/kg/day p.o. for 30 days in each group of ovariectomized rats, SAM R1 and SAM P6. The extract of Cervi parvum Cornu was given for 14 days only. One ml of blood was taken by tail vein at day 0, 7, 14, 21 and 30 days after administration of the extract. Plasma levels of alkaline phosphatase, calcium, creatinine,inorganic phosphate, blood urea nitrogen, cortisol, total $T_3\;and\;total\;T_4$ were measured. In ovariectomized rats, administration of Achyranthis Radix or Corni Fructus decreased in alkaline phosphatase and that of Achyranthis Radix or Psoraleae Radix decreased in calcium comparing to the control (p<0.05). The administration of Psoralese Radix decreased in calcium and increased in urea comparing to day o(P<0.05)(Table I). There were not much changes in plasma calcium, inorganic phosphate, and alkaline phosphatase concentrations after uptake of these herbal medicine used in SAM P6(Table III). However, administration of Astragali Radix altered plasma inorganic phosphate and creatinine levels in SAM R1(p<0.01)(Table UU). The administration of Corni Fructus or Psoralease Radix induced the changes in plasma concentrations of cortisol, total $T_3$ and total $T_4$ in Type I(p<0.05) (Table IV). The uptake of Cervi parvum Cornu increased in total $T_3$ concentration and that of Mycelia of Ganodtragali Radix in SAM P6. However, the uptake of Mycelia of Ganoderma induced changes in cortisol and $T_4$ concentrations in SAM R1(p<0.05). Thus, there were significant differences in responses of herbal medicine in different types of osteoporosis.

• Magazine of the Korea Concrete Institute
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• v.20 no.5
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• pp.53-58
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• 2008

• Journal of Korean Neurosurgical Society
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• v.45 no.5
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• pp.322-322
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• 2009

• Bulletin of the Korean Chemical Society
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• v.13 no.5
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• pp.459-460
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• 1992

• Analytical Science and Technology
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• v.5 no.4
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• pp.359-366
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• 1992

Using micro-Raman spectrometer, we investigated the evaluation of microstress on silicon surface after the local thermal oxidation. The induced stress of silicon surface after local thermal oxidation shows maximum value at the interface of silicon oxide and active area. The smaller the size of active area, the larger stress. From the evaluation of three other device isolation processes, A, B and moB, whose active size has $0.45{\mu}m$ in length, moB process is turned out to have the lowest stress value and the smallest bird's beak effect.