• The Korean Journal of Physiology and Pharmacology
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• v.21 no.5
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• pp.495-507
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• 2017

The effect of clonidine administered intrathecally (i.t.) on the mortality and the blood glucose level induced by sepsis was examined in mice. To produce sepsis, the mixture of D-galactosamine (GaLN; 0.6 g/10 ml)/lipopolysaccharide (LPS; $27{\mu}g/27{\mu}l$) was treated intraperitoneally (i.p.). The i.t. pretreatment with clonidine ($5{\mu}g/5{\mu}l$) increased the blood glucose level and attenuated mortality induced by sepsis in a dose-dependent manner. The i.t. post-treatment with clonidine up to 3 h caused an elevation of the blood glucose level and protected sepsis-induced mortality, whereas clonidine post-treated at 6, 9, or 12 h did not affect. The pre-treatment with oral D-glucose for 30 min prior to i.t. post-treatment (6 h) with clonidine did not rescue sepsis-induced mortality. In addition, i.t. pretreatment with pertussis toxin (PTX) reduced clonidine-induced protection against mortality and clonidine-induced hyperglycemia, suggesting that protective effect against sepsis-induced mortality seems to be mediated via activating PTX-sensitive G-proteins in the spinal cord. Moreover, pretreatment with clonidine attenuated the plasma tumor necrosis factor ${\alpha}$ ($TNF-{\alpha}$) induced by sepsis. Clonidine administered i.t. or i.p. increased $p-AMPK{\alpha}1$ and $p-AMPK{\alpha}2$, but decreased p-Tyk2 and p-mTOR levels in both control and sepsis groups, suggesting that the up-regulations of $p-AMPK{\alpha}1$ and $p-AMPK{\alpha}2$, or down-regulations of p-mTOR and p-Tyk2 may play critical roles for the protective effect of clonidine against sepsis-induced mortality.

• Journal of Korean Society of Forest Science
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• v.80 no.3
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• pp.279-286
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• 1991

This study was carried out to investigate relationships between atmospheric $SO_2$ concentration and both soluble sulphur contents in the tree leaves and bark pH to test the possibility of using them as bioindicators for air pollution. Mt. Kwanak, Mt. Nam, Mt. Bukhan (located in Seoul) and Mt. Paldal (located in Suwon, Kyonggi-do) as polluted areas and Pyongchang, Kwangwon-do as an unpolluted area were selected for this study. Soluble sulphur contents in the leaves and hark pH of two tree species (Pines densiflora S. et Z. and Quercus mongolica Fisch.) were analyzed in May, August, and October, 1990 by $BaSO_4$ precipitation method and pH measurement, respectively. In both species, concentration of soluble sulphur in the leaves increased with increasing concentration of atmospheric $SO_2$ (correlation coefficient : 0.52). Soluble sulphur contents in the 2-year-old needles of Pines densiflora (0.170%) and current year leaves of Quercus mongolica (0.081%) in Mt. Nam in the center of Seoul were higher than those in unpolluted Pyongchang area (0.023% and 0.034%, respectively). Bark pH decreased with increasing atmospheric $SO_2$ concentration (correlation coefficient : -0.52). Bark pH of P. densiflora (pH 3.42) and Q. mongolica (pH 3.63) in Mt. Nam were lower than those in Pyongchang area (pH 3.94 and pH 4.93, respectively). Both soluble S content in the leaves and bark pH were recognized as suitable bioindicators for air pollution by $SO_2$. Especially, bark pH showed more sensitive response to air pollution by $SO_2$ than soluble S concentration in the leaves. The lowest concentration of soluble sulphur and the highest bark pH in August were considered to be due to heavy rain during the rainy season. Soluble S content in the leaves and bark pH were not significantly different at 5% level between the two species in polluted areas.

• The Plant Pathology Journal
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• v.21 no.2
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• pp.127-131
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• 2005

In this comparative study, the effects of temperature, pH, and bactericides on the growth of Erwinia pyrifoliae and Erwinia amylovora were investigated. The maximum temperature for the growth of both Erwinia species was estimated to be $36{\circ}C$. The maximum specific growth rates of E. pyrifoliae and E. amylovora were observed at $27{\circ}C$ and $28{\circ}C$, respectively, and no significant growth differences were shown at their optimum temperatures. However, at lower temperatures ranging from 12-$21{\circ}C$, E. pyrifoliae showed higher growth rates with doubling times shorter than those of E. amylovora. Distinct growth rates at these temperatures revealed that E. pyrifoliae is more cold-tolerant than E. amylovora. The optimum pH for the growth of both pathogens was 7.5 and growth was not seen at pH ${\le}$ 5.0 and ${\ge}$ 10.0. These results showed that the effect of pH on the growth of E. pyrifoliae and E. amylovora was similar. Minimum inhibitory concentrations (MICs) of copper sulfate, oxolinic acid, streptomycin, and tetracycline, which inhibited growth of E. pyrifoliae and E. amylovora, were determined. The strains of both pathogens were able to grow at 0.08-0.32 mM copper sulfate, but not at higher concentrations. However, none of the tested strains grew in the presence of oxolinic acid (0.001 mM), streptomycin (0.1 mM), and tetracycline (0.01 mM) concentrations. These results suggested that all strains of both Erwinia species were sensitive to tested bactericides and indicated no occurrence of resistant strains of E. pyrifoliae in Korea.

• Advances in nano research
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• v.5 no.3
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• pp.245-251
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• 2017

Multiwalled carbon-nanotubes (MWCNT) and micro-structured carbon, such as biochar or activated carbon (AC), have been seen to significantly increase the growth indices of certain plant species such as maize (Zea mays L.). Seed imbibition is the stage where environmental factors that affect water transport across the seed coat barrier, make a large impact. This work explores the effect on water imbibition by maize seeds when the aqueous environment surrounding the seed is diluted by small concentrations (10 and 20 mg/l) of pristine MWCNT (p-MWCNT), carboxylate functionalized MWCNT (COO-MWCNT) and AC. The degree of sensitivity of the process to (i) large structural changes is seen by utilizing the nano (the MWCNT) and the micro (the AC) allotropic forms of carbon; (ii) to small changes in the purity and morphology of the p-MWCNT by utilizing 95% pure and 99% pure p-MWCNTs of slightly differing morphologies; and (iii) to MWCNT functionalization by using highly pure (97%) COO-MWCNT. Water imbibition was monitored over a 15 hour period by Near Infrared Thermography (NIRT) and also by seed weighing. Seed surface topography was seen by SEM imaging. Analysis of the NIRT images suggests rapid seed surface topological changes with the quantity of water imbibed. While further work is necessary to arrive at a conclusive answer, this work shows that the imbibition phase of the maize seed is sensitive to the presence of MWCNT even to small differences in the purity of the p-MWCNT and to small differences in the physicochemical properties of the medium caused by the hydrophilic COO-MWCNT.

• Resources Recycling
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• v.16 no.6
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• pp.39-45
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• 2007

Optimum condition for neutralization has been studied to remove the copper and zinc ions from spent sulfate solutions which resulted from the acid washing of the base of brass bulb. Chemical distribution of copper and zinc species and the variation of solubility of the two ions with solution pH were obtained by considering the complex formation reaction and mass balance. Removal percentage of zinc was more sensitive to solution pH than that of copper. This results from the fact that the solubility of zinc is higher than that of copper. The form of coagulant affected little the removal percentage of zinc, while addition of coagulant as the phase of solution resulted in higher removal percentage of copper than as the phase of solid.

• Molecules and Cells
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• v.40 no.8
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• pp.567-576
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• 2017

The $Na^+/H^+$ exchanger is responsible for maintaining the acidic tumor microenvironment through its promotion of the reabsorption of extracellular $Na^+$ and the extrusion of intracellular $H^+$. The resultant increase in the extracellular acidity contributes to the chemoresistance of malignant tumors. In this study, the chemosensitizing effects of cariporide, a potent $Na^+/H^+-exchange$ inhibitor, were evaluated in human malignant mesothelioma H-2452 cells preadapted with lactic acid. A higher basal level of phosphorylated (p)-AKT protein was found in the acid-tolerable H-2452AcT cells compared with their parental acid-sensitive H-2452 cells. When introduced in H-2452AcT cells with a concentration that shows only a slight toxicity in H-2452 cells, cariporide exhibited growth-suppressive and apoptosis-promoting activities, as demonstrated by an increase in the cells with pyknotic and fragmented nuclei, annexin V-PE(+) staining, a $sub-G_0/G_1$ peak, and a $G_2/M$ phase-transition delay in the cell cycle. Preceding these changes, a cariporide-induced p-AKT down-regulation, a p53 up-regulation, an ROS accumulation, and the depolarization of the mitochondrial-membrane potential were observed. A pretreatment with the phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002 markedly augmented the DNA damage caused by the cariporide, as indicated by a much greater extent of comet tails and a tail moment with increased levels of the p-histone H2A.X, $p-ATM^{Ser1981}$, $p-ATR^{Ser428}$, $p-CHK1^{Ser345}$, and $p-CHK2^{Thr68}$, as well as a series of pro-apoptotic events. The data suggest that an inhibition of the PI3K/AKT signaling is necessary to enhance the cytotoxicity toward the acidtolerable H-2452AcT cells, and it underlines the significance of proton-pump targeting as a potential therapeutic strategy to overcome the acidic-microenvironment-associated chemotherapeutic resistance.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.5
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• pp.22-29
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• 1981

An ion sensitive field effect transistor employing a special HCI heat treatment for the gate oxide layer along with tungsten metallization and multilayer encapsulation using fumed silica epoxy mixture was fabricated and its performance characteristics have been investigated. A theoretical model for the device operation is discussed, and it is shown that the experimental results are in good agreement with the theory. The fabricated device has excellent performance characteristics showing the fast response, long operation-life, small pH hysteresis, high sensitivity, etc. Especially, its stability has been greatly improved.

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.524-526
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• 1998

A sensitive and specific method is described for the determination of midazolam in human plasma. The drug was extracted from 1 mL of carbonate buffered plasma (pH 9.6) with 8 mL of diethyl ether. Famprofazone was used as internal standard. The organic phase was evaporated to dryness. The residue was dissolved in methanol for the direct analysis by gas chromatograph-nitrogen phosphorus detector system. In the concentration range of 1-5000 ng/mL, the calibration curve was linear. The coefficients of variation from the precision test were <6% at the range of the concentration of 0.10-2.00 μg/mL and the detection limit for midazolam in 1 mL of plasma was o.5 ng. This assay is more sensitive, selective, simple and rapid than earlier methods. Plasma midazolam concentrations were determined by this method after administration of midazolam.

• International Journal of Oral Biology
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• v.36 no.2
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• pp.103-108
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• 2011

Measurement of estrogen concentration in bio-samples are very important for differential diagnosis of various disease or evaluation of health status. However, it is difficult to collect immediate data of estrogen concentration because they are measured by radioimmunoassay or chromatography which need time- and cost-consuming sample pre-treatment. This study was performed for development of new estrogen biosensor employing taste principles, and for evaluation of cross reactivity between various steroid hormones. Gene sequence of ligand binding domain of ${\alpha}$-human estrogen receptor (amino acid 302-553; hER-LBD) was cloned from human breast cancer cell line. The proteins of hER-LBD were produced by T7-E.coli expression system, and isolated by chromatography. hER-LBD were coated on the gold plated quartz crystal (AT-cut 9MHz), and resonance frequencies were measured by universal frequency counter. Estradiol, progesterone, testosterone, and aldosterone were used for cross reactivity of the hER-LBD. We also monitored influences of pH change in resonance frequency. The resonance frequencies of hER-LBD coated quartz crystal were decreased during increase of estrogen concentration from $15 \;{\mu}g/mL$ to $50\;{\mu}g/mL$. However, similar steroid hormones, progesterone and aldosterone, did not elicit the change in resonance frequency. Testosterone evoke weak change in resonance frequency. The new estrogen biosensor was more sensitive in pH 7.2 than in pH 7.6. These results suggest that hER-LBD coated quartz crystal biosensor is a probable estrogen biosensor.

• YAKHAK HOEJI
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• v.37 no.4
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• pp.362-364
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• 1993

The sensitive detection of free fatty acids was investigated by using H$_{2}$O$_{2}$-bis(2,4,6-trichlorophenyl) oxalate chemiluminescence system after monodansyl cadaverine labeling. Because dansvl moiety is well excited by this chemiluminescence system, monodansyl cadaverine was a prominent reagent to this system for the determination of free fatty acids. The cluent of 50mM tris-HCI buffer (pH 7.7)-acetonitrile (1:4, v/v) was run through TSK gel ODS 80 TM column. The reagent solutions were mixed with the eluent containing the monodansyl cadaverine derivative of fatty acids from the column. By this system, linolic acid was detected 50 fmol by injected amount.