• The Korean Journal of Physiology
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• v.13 no.1_2
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• pp.41-50
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• 1979

The activation mechanism of K-induced contracture was studied in renal vascular muscle which does not generate an action potential readily and in taenia coli which generates a spike potential spontaneously. Helical strips of arterial muscle from rabbit renal arteries and longitudinal strips of taenia coli from guinea-pig's colons, respectively, were prepared. All experiments were performed in Tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept $35^{\circ}C$. Renal arterial muscles developed the contracture rapidly, which was composed of a small phasic and a large tonic components, when exposed to a 40 mM K-Tyrode solution. In the absence of external $Ca^{++}$, however, no K-contracture appeared. The contracture induced by K-depolarization was abolished by the treatment with verapamil, which is known to be a selective $Ca^{++}-blocker$ through potential-sensitive $Ca^{++}-channel$. K-contracture of taenia coli showed the contracture composed of a large phasic and a small tonic components. In the $Ca^{++}-free$ Tyrode solution, only the tonic component was abolished and almost no change in the phasic component was observed. The amplitude of tonic component was dependent on the external $Ca^{++}$; The tonic component increased dose-dependently by a stepwise increase of the external $Ca^{++}$, and this component decreased in parallel with the increase of verapamil in the external medium. The results of this experiment suggest that K-contracture of rabbit renal artery is the direct result of the influx of the external $Ca^{++}$, while that of taenia coli is the result of both $Ca^{++}$ influx and the release of sequestered $Ca^{++}$.

• Plant Biotechnology Reports
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• v.3 no.2
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• pp.157-165
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• 2009

Human erythropoietin (EPO) is a leading product in the biopharmaceutical market, but functional EPO has only been produced in mammalian cells, which limits its application and drives up the production costs. Using plants to produce human proteins may be an alternative way to reduce the cost. However, a recent report demonstrated that overexpression of the human EPO gene (EPO) in tobacco or Arabidopsis rendered males sterile and retarded vegetative growth, which raises concern whether EPO might interfere with hormone levels in transgenic plants. In the present study, we demonstrated that overexpressing EPO with additional 5'-His tag and 3' ER-retention peptides in tobacco did not cause any developmental defect compared to GUS plants. With our method, all 20 transgenic plants grew on selective medium and, further confirmed by PCR, were fertile. Most of them grew similarly compared to GUS plants. Only one transgenic plant (EPO2) was shorter in plant height but had twice the life span compared to other transgenic plants. When 11 randomly selected EPO plants, along with the abnormal plant EPO2, were subjected to RT-PCR analysis, all of them had detectable EPO transcripts. However, their protein levels varied considerably; seven of them had detectable EPO proteins analyzed by western blot. Our results indicate that overexpressing human EPO protein in plants does not have detrimental effects on growth and development. Our transformation systems allow us to further explore the possibility of glycoengineering tobacco plants for producing functional EPO and its derivatives.

• Mass Spectrometry Letters
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• v.6 no.3
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• pp.71-74
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• 2015

Low temperature plasma (LTP) ionization mass spectrometry (MS) is one of the widely used ambient analysis methods which allows soft-ionization and rapid analysis of samples in ambient condition with minimal or no sample preparation. One of the major advantages of LTP MS is selective analysis of low-molecular weight, volatile and low- to medium-polarity analytes in a sample. On the contrary, the selectivity for particular class of compound also implies its limitation in general analysis. One of the critical factors limiting LTP ionization efficiency is poor desorption of analytes with low volatility. In this study, a home-built LTP ionization source with Peltier heating sample stage was constructed to enhance desorption and ionization efficiencies of analytes in a sample and its performance was evaluated using standard mixture containing fatty acid ethyl esters (FAEEs). It was also used to reproduce the previous bacterial identification experiment using pattern-recognition for FAEEs. Our result indicates, however, that the bacterial differentiation from FAEE pattern recognition using LTP ionization MS still has many limitations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.86-91
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• 1989

Since most chemicals effect to the non-target organisms, present study was conducted to determine the effects of some herbicides to soybean nodule bacteria(Rhizobium japonicum) in vitro. Selective upland herbicides Alachlor, Linuron, Simazine and nonselective Paraquat were medicated to the YEMA media and survival rate of the bacteria in the medium was measured a week after incubation. Survival of soybean nodule bacteria in the media medicated with recommended concentration 400 ppm of Alachlor and Linuron were decreased significantly by 27.4 ％ and 57.8 ％, respectively. While little effect was observed in Simazine, a marked reduction of survival was observed in 200 ppm of Paraquat. Effects of Alachlor was different with isolates of the nodule bacteria. Isolate I -122 was relatively resistant and I -145 was more sensitive. than other isolates tested. Intermediate K-5 was the most resistant at the recommended dose and the survival dose was drastically reduced with increment of concentration. Nodule formation of the soybean plants was different with the varieties and isolates. The most nodulation was observed in the resistant isolates I -122 and K-S, for which the nodulation might be related with the resistance to the environmental stress factors.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.68-78
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• 2006

In the past few years, considerable efforts have been directed towards the further development of Urea-SCR(selective catalytic reduction) technique for diesel-driven vehicle. Although urea possesses considerable advantages over Ammonia$(NH_3)$ in terms of toxicity and handling, its necessary decomposition into Ammonia and carbon dioxide complicates the DeNOx process. Moreover, a mobile SCR system has only a short distance between engine exhaust and the catalyst entrance. Hence, this leads to not enough residence times of urea, and therefore evaporation and thermolysis cannot be completed at the catalyst entrance. This may cause high secondary emissions of Ammonia and isocyanic acid from the reducing agent and also leads to the fact that a considerable section of the catalyst may be misused for the purely thermal steps of water evaporation and thermolysis of urea. Hence the key factor to implementation of SCR technology on automobile is fast thermolysis, good mixing of Ammonia and gas, and reducing Ammonia slip. In this context, this study performs three-dimensional numerical simulation of urea injection of heavy-duty diesel engine under various injection pressure, injector locations and number of injector hole. This study employs Eulerian-Lagrangian approach to consider break-up, evaporation and heat and mass-transfer between droplet and exhaust gas with considering thermolysis and the turbulence dispersion effect of droplet. The SCR-monolith brick has been treated as porous medium. The effect of location and number of hole of urea injector on the uniformity of Ammonia concentration distribution and the amount of water at the entrance of SCR-monolith has been examined in detail under various injection pressures. The present results show useful guidelines for the optimum design of urea injector for reducing Ammonia slip and improving DeNOx performance.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.292-303
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• 1998

The arbitrary primer polymerase chain reaction(AP-PCR) and Southern blot restriction fragment length polymorphism(RFLP) were used to genotype the cariogenic pathogen S. mutans in children. Following the morphologic chracteristics of colony on selective medium for S. mutans, total genomic DNA from 155 strains was extracted by conventional methods. Among 155 strains, 143 strains (92.3%) were confirmed S. mutans by PCR with dexA gene and 114 strains were used in this study. Three random sequence 10-base oligonucleotide primers were chosen for AP-PCR. The amplified DNA products were separated electrophoretically in a 2% agarose gel containing ethidium bromide and the banding patterns were compared among different strains. For RFLP analysis, DNA was digested with EcoRI and BamHI, separated on a 0.7 % agarose gel and transferred to a nylon membrane. The membrane was probed with a previously characterised 1.6 kilobases (kb) DNA fragment cloned from gtf B gene of S. mutans. The probe was labeled with isotope[$^{32}P-{\alpha}CTP$], and hybridized fragments were detected with intensifying screen. AP-PCR produced 4-8 DNA bands in the 0.25-10 kb regions and distinguished 9, 10 or 12 genotypes, depending on the specific primer used. Southern blot RFLP analysis revealed 2 hybridization patterns consisting of 1 DNA fragments 450, 500 bp. These results indicate that AP-PCR is more discriminative method for genotyping of S. mutans.

• The Journal of Korean Obstetrics and Gynecology
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• v.20 no.1
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• pp.50-60
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• 2007

Purpose : This investigation was undertaken to evaluate the anti-proliferation, in hexane, chloroform, ethyl acetate, butanol and water fraction from extract of Gyulyupsanbyonbang(GYSB) using MCF-7 human breast cancer cells. Methods : GYSB was added to distilled water(1500ml) and was boiled then filtered. The residue was suspended in distilled water and extracted with hexane, chloroform, ethyl acetate, butanol and water. MCF-7 cells were cultured in RPMI1640 complex badge, NIH3T3 was cultered in 37$^{\circ}$C, 5% moisture incubator of carbon dioxide with Dulbecco's Modified Eagle Medium(DMEM) supplemented with 10% fetal bovine serum and antibiotics. Cell cytotoxicity test about cancer cell was measured used MTT assay. Results: When it synthesizes a result, hexane and butanol fraction had shown anti-proliferation effect and safety together, and those anti-proliferation effect operating selectively appeared. Ethyl acetate fraction had anti-proliferation effect however, it was not selective. The Chloroform and water soluble fraction did not almost appear anti-proliferation effect. Conclusion : I can conclude that GYSB have anti-proliferation effect and safety together on MCF-7 cells. It suggest that GYSB may be useful for brest cancer patients.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.367-376
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• 1997

Vibrio vulnificus is a gram-negative, halophilic, oxidase-positive, lactose-positive, motile, rod shaped bacterium that has been associated with primary septicemia and wound infection. Elucidating the growth and survival of V. vulnificus in ecological conditions is of great importance to develop sanitary measure against this microorganism. Thus we simulated the ecological conditions and evaluated the effect. About $10^5\;CFU/ml$ of V. vulnificus was inoculated to fresh water, brackish water $(1\%\;NaCl)$, sea water $(3\%\;NaCl)$, and bottom deposit solution. The same concentration of V. vulnificus was also inoculated to distilled water, $1\%\;NaCl$ solution and $3\%\;NaCl$ solution as controls. These were stored at 4, 15 and $25^{\circ}C$, respectively and were used to assess the effects of temperature and salinity on the survival of V. vulnificus. In fresh water V. vulnificus could not survive regardless of storage temperature. In case of brackish water and sea water survival time of V. vulnificus was the longest at $25^{\circ}C$, and the number of V. vulnificus was decreased most rapidly at $4^{\circ}C$. V. vulnificus survived longer in brackish water than in any other conditions. In bottom deposit solution containing brackish water, the survival time of V. vulnificus was longer and the rate of decline was slower than that in brackish water. These results indicate that both biological and physicochemical factors such as temperature and salinity could affect survival of V. vulnificus. V. vulnificus, damaged in normal fresh water, did not grow on TCBS agar of selective plating medium but grew on BHI agar plate; However, V. vulnificus was recovered by addition of salt and nutrient materials.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.520-525
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• 1990

A modified method of urea adduct formation, in which water and organic solvent were used as the wetting agent and the reaction medium. respectively, is suggested to obviate methanolysis and to ease recovery in the separation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil. With the new method the fraction in which the total content of EPA. DHA and their precursors is more than 80% could be obtained. Although the total content of precursors in the concentrate was hardly affected by the kind of the wetting agent or the organic solvent, the content of EPA and DHA varied significantly depending on the organic solvent. This finding made it possible to selectively enrich the desired components. After DHA-enriched fraction (I)HA is 50%) was obtained by using pentane, EPA-enriched fraction ( EPA is 53%)) could be obtained from the residue of DHA-enriched fraction by using heptane.

• Industry Promotion Research
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• v.1 no.1
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• pp.159-166
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• 2016

The purpose of this study is to present and identify the relationship for the effects of performance-based human resource practices on the organizational effectiveness with focusing on small and medium-sized enterprises around Shandong province of China. The performance-based human resource practice factors include selective employment system, education training system, evaluation system, compensation system and the career promotion ladder opportunity system. As a result, among ten hypotheses, six hypotheses turned out to be the meaningful approaches. In addition there exist some human factors that interfere with the fairness of the evaluation due to the regional and personal factors, assessment system difference among firms. Finally the compensation system and organizational investment for increasing or decreasing will critically affect the enthusiasm of the staff members of firms, and the less invested for thema, the greater the likelihood of their turnovers.