• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.4
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• pp.99-107
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• 2003

Normally coating is used a method for protecting reinforced concrete. For this purpose, organic as well as inorganic coatings are used. The advantages of inorganic coatings are lower absorption of UV, non-burning etc. On the other hand, organic coatings have the advantage of low permeability of $CO_2$, $SO_2$ and water. Organic coatings provide better protection for reinforced concrete. However, in organic coatings such as epoxy, urethane and acryl, long-term adhesive strength is reduced and the formed membrane of those is blistered by various causes. Also when organic coatings are applied to the wet surface of concrete, they have a problem with adhesion. So, we developed coating material, WGS-Eco which was hybridized with polymer and cement based material to protect concrete structures and solve problems of organic coatings. This study was conducted an comparative evaluation on physical and durable performance of developed coating material and previously used coating materials. As a result, the performance of developed coating material was not inferior to organic coating materials. So, the developed coating material was considered as a suitable coating material which had advantages of inorganic and organic coatings for protecting concrete.

• Journal of Chest Surgery
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• v.43 no.4
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• pp.345-355
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• 2010

Background: Extracellular and intracellular pH ($pH_o$ and $pH_i$), which can be changed in various pathological conditions such as hypoxia, affects vascular contractility. To elucidate the mechanism to alter vascular contractility by pH, the effects of pH on reactivity to vasocontracting agents, intracellular $Ca^{2+}$ influx, and $Ca^{2+}$ sensitivity in vascular smooth muscle were examined. Material and Method: Isometric contractions in rat superior mesenteric arteries (SMA) were observed. Intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) was recorded by microfluorometer using Fura-2/acetoxylmethyl ester in muscle cells. $pH_o$ was increased from 7.4 to 7.8 or decreased to 6.9 or 6.4. $pH_i$ was decreased by applying $NH_4^+$ or propionic acid or modulated by changing $pH_o$ after increasing membrane permeability using $\beta$-escin. Result: Decreases in $pH_o$ from 7.4 to 6.9 or 6.4 shifted concentration-response curve by norepinephrine (NE) or serotonin (SE) to the right and significantly increased half maximal effective concentration (EC50) to NE or SE. Increase in $pH_o$ from 7.4 to 7.8 shifted concentration-response curve by norepinephrine (NE) or serotonin (SE) to the left and significantly reduced EC50 to NE or SE. NE increased $[Ca^{2+}]_i$ in cultured smooth muscle cells from SMA and the increased $[Ca^{2+}]_i$ was reduced by decreases in $pH_o$. NE-induced contraction was inhibited by $NH_4^+$, whereas the resting tension was increased by $NH_4^+$ or propionic acid. When the cell membrane of SMA was permeabilized using ${\beta}$-escin, SMA was contracted by increasing extracellular $Ca^{2+}$ concentration from 0 to $10{\mu}M$ and the magnitude of contraction was decreased by a decrease in $pH_o$ and vice versa. Conclusion: From these results, it can be concluded that a decrease in $pH_o$ might inhibit vascular contraction by reducing the reactivity of vascular smooth muscle to vasoactive agents, $Ca^{2+}$ influx and the sensitivity of vascular smooth muscle to $Ca^{2+}$.

• Journal of Life Science
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• v.31 no.11
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• pp.1028-1036
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• 2021

Firefly luciferase (FLuc) can function as an efficient marker in the gene and viral therapies. Nonetheless, its clinical translation has been unaccomplished with the concerns on its exogenous nature and the similarity with human fatty acyl-CoA synthetase. In this study, we aimed to show safety of FLuc by conducting a set of preclinical experiments and a human use. Initially, FLuc permeability across the plasma membrane was investigated by delivering the FLuc-carrying viral vector, OTS-412, or the FLuc recombinant protein. After in vitro infection of OTS-412 into different cancer cell lines, FLuc activity was detected only in the cell lysates, but not in culture media. In addition, recombinant FLuc protein further showed the impermeability against the plasma membrane. Similar result was also observed in the in vivo experiment. After being injected into the VX2 tumor-bearing rabbit, the FLuc exclusively resided within the tumor tissue without being detected in the blood plasma or other organs. Human cancer cell lines originated from various organs were lysed and treated to the FLuc, and none of the human substrates was reactive against the FLuc. As a final step, FLuc recombinant protein was intravenously injected into a human. The luciferase was degraded with the half-life of 20 to 30 minutes in blood, and was untraceable from 1.5 hr after the injection. In addition, the blood plasma was nonresponsive against the fatty acids. Hematological analysis was also comparable between the pre- and post-injection. Altogether, our study collectively demonstrates the safety of the firefly luciferase.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.5
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• pp.731-738
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• 2011

Cholesterol is the precursor of various steroid hormones, bile acid, and vitamin D with functions related to regulation of membrane permeability and fluidity. However, the presence of excess blood cholesterol may lead to arteriosclerosis and hypertension. Moreover, dietary cholesterol may affect blood cholesterol levels. Generally, cholesterol determination is performed by spectrophotometric or chromatographic methods, but these methods are very time consuming and costly, and require complicated pretreatment. Thus, the development of a rapid and simple analysis method for measuring cholesterol concentration in food is needed. Multi-walled carbon nanotube (MWCNT) was functionalized to MWCNT-$NH_2$ via MWCNT-COOH to have high sensitivity to $H_2O_2$. The fabricated MWCNT-$NH_2$ was attached to a glassy carbon electrode (GCE), after which Prussian blue (PB) was coated onto MWCNT-$NH_2$/GCE. MWCNT-$NH_2$/PB/GCE was used as a working electrode. An Ag/AgCl electrode and Pt wire were used as a reference electrode and counter electrode, respectively. The sensitivity of the modified working electrode was determined based on the amount of current according to the concentration of $H_2O_2$. The response increased with an increase of $H_2O_2$ concentration in the range of 0.5~500 ${\mu}M$ ($r^2$=0.96) with a detection limit of 0.1 ${\mu}M$. Cholesterol oxidase was immobilized to aminopropyl glass beads, CNBr-activated sepharose, Na-alginate, and toyopearl beads. The immobilized enzyme reactors with aminopropyl glass beads and CNBr-activated sepharose showed linearity in the range of 1~100 ${\mu}M$ cholesterol. Na-alginate and toyopearl beads showed linearity in the range of 5~50 and 1~50 ${\mu}M$ cholesterol, respectively. The detection limit of all immobilized enzyme reactors was 1 ${\mu}M$. These enzyme reactors showed high sensitivity; especially, the enzyme reactors with CNBr-activated sepharose and Na-alginate indicated high coupling efficiency and sensitivity. Therefore, both of the enzyme reactors are more suitable for a cholesterol biosensor system.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.243-249
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• 2006

Porous polymer gel electrolytes (PGEs) based on poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) as a polymer matrix and polyvinylpyrolidone (PVP) as a pore-forming agent were prepared and electrochemical properties were investigated for an electric double layer capacitor (EDLC) in order to increase a permeability of an electrolyte into the PGE. Propylene carbonate (PC) and ethylene carbonate (EC) as plasticizers, and tetraethylammonium tetrafluoroborate ($TEABF_4$) as a supporting salt for the PGE were used. EDLC unit cells were assembled with the PGE and electrode comprising BP-20 and MSP-20 as activated carbon powders, Super P as a conducting agent, and P(VdF-co-HFP)/PVP as a mixed binder. Ion conductivity of PGEs increased with an increased PVP content and was the best at 7 wt% PVP, whereas electrochemical characteristics such as AC-ESR of unit cell were better in 3 wt%. And electrochemical characteristics of the unit cell with PGE were the best at a 33 : 33 weight ratio of PC to EC. Specific capacitance of a mixed plasticizer system of PE and EC was higher than that of pure PC. Ion conductivity of PGEs with a film thickness of $20{\mu}m$ was higher, but electrochemical characteristics of unit cells were higher for a $50{\mu}m$ membrane thickness. Also, the unit cell has shown the highest capacitance of 31.41 F/g and more stable electrochemical performance when PGE and electrode were hot pressed. Consequently, the optimum composition ratio of PGE for EDLCs was 23 : 66 : 11 wt% such as P(VdF-co-HFP) : PVP = 20 : 3 wt% and PC : EC = 44 : 22 wt%. In this case, $3.17{\times}10^{-3}S/cm$ of ion conductivity was achieved at the $50{\mu}m$ thickness of PGE for EDLCs. And the electrochemical characteristics of unit cells were $2.69{\Omega}$ of DC-ESR, 28 F/g of specific capacitance, and 100% of coulombic efficiency.

• 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.