• The Korean Journal of Nuclear Medicine
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• v.36 no.6
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• pp.333-343
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• 2002

Purpose: A new linker, hydrazino nicotinamide (HYNIC), was recently introduced for labelling of liposome with $^{99m}Tc$. In this study we synthesized HYNIC derivatized PEG (polyethylene glycol)-liposomes radiolabeled with $^{99m}Tc$. Materials and Methods: In order to synthesize HYNIC-DSPE (distearoyl phosphatidyl ethanolamine) which is a crucial component for $^{99m}Tc$ chelation, first of all succinimidyl 6-BOC-hydrazinopyridine-3-carboxylic acid was synthesized from 6-chloronicotinic acid by three sequential reactions. A DSPE derivative of succinimidyl 6-BOC-hydrazinopyridine-3-carboxylic acid was transformed into HYNIC-DSPE by HCI/dioxane. HYNIC-PEG-liposomes were prepared by hydration of the dried lipid mixture of EPC (egg phosphatidyl choline): PEG-DSPE : HYNIC-DSPE:cholesterol (1.85:0.15:0.07:1, molar ratio). The HYNIC-PEG-liposomes were labeled with $^{99m}Tc$ in the presence of $SnCl_2{\cdot}2H_2O$ (a reducing agent) and tricine (a coligand). To investigate the level of in vivo transchelation of $^{99m}Tc$ in the liposomes, the $^{99m}Tc$-HYNiC-PES-liposomes were incubated with a molar excess of DTPA, cysteine or glutathione solutions at $37^{\circ}C$ for 1 hour. The radiolabeled liposomes were also incubated in the presence of human serum at $37^{\circ}C$ for 24 hours. Results: 6-BOC-hydrazinopyridine-3-carboxylic acid was synthesized with 77.3% overall yield. The HYNIC concentration in the PEG-coated liposome dispersion was 1.08 mM. In condition of considering the measured liposomal size of 106 nm, the phospholipid concentration of $77.5\;{\mu}mol/m{\ell}$ and the liposomal particle number of $5.2{\times}10^{14}$ liposomes/ml, it is corresponded to approximate 1,250 nicotinyl hydrazine group per liposome in HYNIC-PEG-liposome. The removal of free $^{99m}Tc$ was not necessary because the labeling efficiency were above 99%. The radiolabeled liposomes maintained 98%, 96% and 99%, respectively, of radioactivity after incubation with transchelators. The radiolabeled liposomes possessed above 90% of the radioactivity in serum. Conclusion: These results suggest that the HYNIC can be synthesized easily and applied in labelling of PEG-liposomes with $^{99m}Tc$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.455-462
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• 2000

The objective of this study was to examine the physicochemical characteristics of coagulation reaction between loess and red tide organisms (RTO) and its feasibility, in developing a technology for the removal of RTO bloom in coastal sea. The physicochemical characteristics of loess were examined for a particle size distribution, surface characteristics by scanning electron microscope, zeta potential, and alkalinity and pH variations in sea water. Two kinds of RTO that were used in this study, Cylindrothen closterium and Skeietonema costatum, were sampled in Masan bay and were cultured in laboratory. Coagulation experiments were conducted using various concentrations of loess, RTO, and a jar tester. The supernatant and RTO culture solution were analyzed for pH, alkalinity, RTO cell number. A negative zeta potential of loess increased with increasing pH at $10^(-3)M$ NaCl solution and had -71.3 mV at pH 9.36. Loess had a positive zeta potential of +1,8 mV at pH 1.98, which resulted in a characteristic of material having an amphoteric surface charge. In NaCl and $CaCl_2$, solutions, loess had a decreasing negative zeta potential with increasing $Na^+\;and\;Ca^(+2)$ ion concentration and then didn't result in a charge reversal due to not occurring specific adsorption for $Na^+$ ion while resulted in a charge reversal due to occurring specific adsorption for $Ca^(+2)$ ion. In sea water, loess and RTO showed the similar zeta potential values of -112,1 and -9.2 mV, respectively and sea sand powder showed the highest zeta potential value of -25.7 mV in the clays. EDLs (electrical double-layers) of loess and RTO were extremely compressed due to high concentration of salts included in sea water, As a result, there didn't almost exist EDL repulsive force between loess and RTO approaching each other and then LVDW (London-yan der Waals) attractive force was always larger than EDL repulsive force to easily form a floe. Removal rates of RTO exponentially increased with increasing a loess concentration. The removal rates steeply increased until $800 mg/l$ of loess, and reached $100{\%}$ at 6,400 mg/l of loess. Removal rates of RTO exponentially increased with increasing a G-value. This indicated that mixing (i.e., collision among particles) was very important for a coagulation reaction. Loess showed the highest RTO removal rates in the clays.

• Journal of the Korean Geographical Society
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• v.29 no.1
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• pp.16-38
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• 1994

The spatial structure of Korea has been changed drastically during the second half of this century. The events such as the Korean War and the resultant division of the Korean Peninsular into two Koreas, rapid industrialization and urbanization are the major causes among others for the spatial changes of the nation. The changes in turn have spawned a number of spatial problems. It is time, we argue, to diagnose how much the nation is now ill-structured, and to discuss of which directions the long-term spatial management be reoriented. A delphi survey was conducted during the early 1993 to fulfill such research needs. Questionnaires were distributed among geographers, planners, and high governmental officials throughout the nation. These 'experts of spatial problems' were requested to evaluate the past spatial policies and strategies, and to identify spatial and environmental problems at the national, regional and local levels. The survey included questions with regard to the spatial problems in North Korea too. A complementary literature survey in the fields of spatial sciences was accomplished as well in order to identify the major research interests and issues with regard to the nations's spatial structure. The delphi survey results indicatee that the present spatial structure: in relation to consumption, housing and economic activities is satisfactory in overall, while rather poor in terms of education, leisure and community activities. Most of the experts consider infrastructural improvements are urgent in the areas of roads, waste disposal facilitles, railroads, harbors, water supply and drainage systems. The over-concentration of economic, social and political function in the Seoul Metropolitan Region is perceived to be the most serious spatial problem in Korea. The long-term solutions suggested are strategies toward a more balanced regional development as well as toward a cleaner environment. The concensus among the experts for the short-term solution is the redistribution of population and industries from the Seoul Metropolitan Region to the intermediate and small cities. The land use policies and concurrent large-scale infrastructural projects are evaluated largely pertinent and desirable in general. It is, however, suggested that development projects be conducted in a more harmonious way with environment. The survey respondents suggest that the present environmental management policies should be reexamined critically. With regard to regional and local problems, transportation and pollutions are thought to be most serious in the Seoul Metropolitan Region, while employment opportunities, and information, education and health care services are most deprived in small cities and rural areas. The majority of the experts consider a city size of 250, 000-500, 000 population is desirable to live within. Respondents beileve that North Korea's physical environment is still not aggravated much whereas its infrastructural provisions are largely pool. The co-authors of this research figure a "environmentaly sound and spatially balanced Korean Penninsular" as the ideal type of spatial structure in Korea. The basic guidelines toward this ideal prototype are suggested: the recovery of spetial integrity, progressive restructuring of the nation, land uses geared to public welfare rather than private interests, and eco-humanistic approach in spatial policies.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.336-341
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• 2000

This study was conducted to clarify the habitat characteristics and distribution of seagrass. Zostera marina L. (Zosteraceae) in the brackish Hwajinpo Lake, Korea in June 1998 and July 2000. Z. marina beds were distributed along the sea-side cost of the lower lake mouth at 0.8 to 1.5m in death, and the seagrass bed area was about 3,200 m$^{2}$. Salinity, water temperature and pH were in the range of 8.0${\sim}$23.0$%_{o}$, 22.0${\sim}$23.7$^{\circ}C$ and 8.34${\sim}$8.62, respectively. Nutrient concentrations were generally now (TN: 24.34 ${\mu}$M, NH$_{4}$-N: 2.57 ${\mu}$M, NO$_{3}$-N: 0.56 ${\mu}$M, NO$_{2}$-N: 0.27 ${\mu}$M, TP: 2.08 ${\mu}$M, PO$_{4}$-P: 0.34 ${\mu}$M). Suspended particulate matters (SPM) concentration averaged 62.8 mg/l and particulate organic matter (POM) averaged 21.3 mg/l. Organic content of SPM averaged 33.9%. The beds substratum was composed of well-sorted, fine sand and its mean brain size was 3.13${\Phi}$. The Z. marina vegetation was almost submerged, and the morphological characteristics can be classified as steno-leaf phenotype by the shoot length, leaf width, and number of leaf vein. Shoot length and leaf width were 70.0${\sim}$126.5 cm and 5${\sim}$7 mm, respectively. Shoot densities ranged from 264 to 296/m$^{2}$, and the plants biomass was estimated at 332.6 to 373.0 g dw/m$^{2}$. Therefore, the habitats of Z. marina in Korea were recognized in a brackish lake, and morphological characteristics appeared to be variable.

• Journal of Life Science
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• v.32 no.6
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• pp.447-454
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• 2022

In this study, we confirmed the effect of HK shiitake mushroom mycelium (HKSMM) on immune enhancement in Balb/c mice. Experimental animals were divided into five groups: negative control (NC), positive control (PC; 1,000 mg/100 g; AHCC), T1 (500 mg/100 g; HKSMM), T2 (1,000 mg/100 g; HKSMM), and T3 (2,000 mg/100 g; HKSMM), and dissection was performed at four and six weeks. COX-2 and iNOS concentrations were significantly lower in the six-week experimental group than in the control group, and the NO results were also similar. Results of the confirmation of the factors related to the NF-κB (p-p65 and p-IκBα) and MAPK (pERK, pJNK, and p38) signaling pathways revealed that the HKSMM-fed experimental group significantly decreased compared with the control group. A comparative analysis of the number and size of white pulp in the spleen tissue showed that those of the experimental group were significantly higher than those of the control group in a concentration-dependent manner. These results suggest that HKSMM has both immune-enhancing and anti-inflammatory effects in Balb/c mice, indicating that it can be used as a health functional food ingredient.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.448-454
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• 2000

This study was to examine the physicochemical characteristics of coagulation reaction between ignited oyster shell powder (IOSP) and red tide organisms (RTO), and its feasibility, in developing a technology for the removal of RTO bloom in coastal sea,IOSP was made from oyster shell and its physicochemical characteristics were examined for particle size distribution, surface characteristic by scanning electron microscope, zeta potential, and alkalinity and pH variations in sea water. Two kinds of RTO that were used in this study, Cylindrotheca closterium and Skeletonema costatum, were sampled in Masan bay and were cultured in laboratory. Coagulation experiments were conducted using various c(Incentrations of IOSP, RTO, and a jar tester. The supernatant and RTO culture solution were analyzed for pH, alkalinity, RTO cell number, IOSP showed positive zeta potentials of $11.1{\~}50.1\;mV\;at\;pH\;6.2{\~}12.7$, A positive zeta potential of IOSP slowly decreased with decreasing pNa 4,0 to 2,0. When pNa reached zero, the zeta potential approached zero, When a pMg value was decreased, the positive zeta potential of IOSP increased until pMg 3.0 and decreased below pMg 3.0. IOSP showed 4.8 mV of positive zeta potential while RTO showed -9.2 mV of negative zeta potential in sea water. A positive-negative EDL (electrical double-layer) interaction occurred between $Mg(OH)_2$ adsorption layer of IOSP and RTO in sea water so that EDL attractive force always worked between them. Hence, their coagulation reaction occurred at primary minimum on which an extreme attractive force acted because of charge neutralization by $Mg(OH)_2$ adsorption layer of IOSP. As a result, the coagulation reaction was rapidly processed and was irreversible according to DLVO (Deriaguin-Landau-Verwey-Overbeek) theory. Removal rates of RTO were exponentially increased with increasing both IOSP concentration and G-value. The removal rates were steeply increased until 50 mg/l of IOSP and reached $100{\%}\;at\;400\;mg/l$ of IOSP. Removal rates of RTO were $70.5,\;70.5,\;81.7,\;85.3{\%}$ for G-values of $1,\;6,\;29,\;139\;sec^(-1)$at IOSP 100 mg/l, respectively. This indicated that mixing (i.e., collision among particles) was very important for a coagulation reaction.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.1
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• pp.47-55
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• 1999

Applications of chitosan are related to molecular weight and degree of deacetylation(DOD) of chitosan completely. The molecular weight and DOD were greatly affected by the concentration of solution time and temperature. The degree of demineralization was not significantly different at $50^{\circ}C\;and\;70^{\circ}C$ after 30 minutes. Deproteinization decreased as process time increased. The nitrogen content was reached to 6.92% after 90 minute at $80^{\circ}C$, which is similar to theoretical nitrogen content of chitin. The DOD was 82.84% after 2 hours reaction and increased as the reaction time increased in the process. Viscosity and molecular weight are increased as recycling number of concentrated NaOH solution increased. Chemical, biological and physical properties of chitosan depend on the DOD and molecular size of the molecule. Tensile strength of the films from acetic acid solutions was between $28.9{\sim}33.6$ MPa and was generally higher than that of the films from lactic acid. Elongation of the films from lactic acid was between $97.0{\sim}109.7%$ and was generally higher than that of the films from the acetic acid. Water vapor permeability of the films prepared from lcetic acid solutions was between $1.9{\sim}2.3ng{\cdot}m/m^2{\cdot}s{\cdot}Pa$ and was generally higher than that of the films from the acetic acid.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.3
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• pp.59-71
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• 2019

The domestic unemployment rate is now seriously increasing due to the impact of the international trend of incurring high costs using only a small number of manpower in a situation where the business has been being reduced in size. The nation is taking start-up promotion policies as a way to overcome the problem, but with the advent of excessive entrepreneurs and their concentration on specific areas, their survival is in an unclear situation. Thus, this study was intended to provide a useful direction for successful start-ups by identifying the impact of entrepreneurial motivation and entrepreneurship, internal characteristics of entrepreneurs, and of competency characteristics, external characteristics of them, on sustainability through business performance. Thus, the purpose of this study was to provide a useful direction for successful start-ups by identifying the impact of entrepreneurial motivation and entrepreneurship, internal characteristics of entrepreneurs, competency, and external characteristics, on sustainability through business performance. The result of verifying the hypothesis has showed that entrepreneurial motivation, entrepreneurship, and competency characteristics had a positive effect on business performance, and on the other hand, the business performance had a positive effect on sustainability. In addition, in terms of the impact of entrepreneurial motivation, entrepreneurship, and competency characteristics on sustainability, all of them had mediating effects on business performance. It is obvious that studies on the factors affecting business performance and corporate sustainability up to now have been carried out by only collecting the independent variables of this study individually or two of them. so it is judged that if the study, which has verified the practical direction in general through the verification of entrepreneurs's internal and external characteristics from various angles, is performed more comprehensively along with the addition of background characteristics of entrepreneurs, such as characteristics of start-up preparation, etc., in the future, more in-depth results will be able to be obtained.

• The Korean Journal of Mycology
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• v.27 no.2 s.89
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• pp.87-93
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• 1999

This study was conducted to investigate the morphological characteristics and cultural conditions for artificial fruiting body(synnemata) production of Paecilomyces japonica. In the morphological characteristics of P. japonica, the size of it's conidia was ranged from $5.0{\sim}1.5\;to\;7.9{\sim}2.4\;{\mu}m$. The artificial fruiting body showed yellow in color, shape was confirmed ellipsoidal or obovoid type, and the length was $50.6{\sim}104.5\;mm$. The mycelial growth on the PDA medium treated with pH7, at $25^{\circ}C$ was superior to that of other treatments. The formation period of an artificial fruiting body of P. japonica treated with polypropylene and glass bottle culture was 30 days and 50 days, respectively. The length and number of fruiting body was longer and higher in the polypropylene bottle culture than those of the glass bottle culture. As the results, the artificial fruiting body production in the polypropylene bottle increased 1.2g per bottle compared to that of the glass bottle. It also increased in $100{\sim}400\;lx$ illumination, whereas the elongation of synnemata, pinheading and fruiting body growth were inhibited by continuous use of 900 lx illumination. The results of these experiment indicated that fruiting body formation seemed to be lower as the light intensity increased. The fruiting body formation was also dependent on the light color. There was a higher incidence in red color light and fluorescent light treatment than that of incandescent and blue color light. The fruiting body of the naked barley medium had so much better growth compared to other media that it would be able to use for it's production. The growth of fruiting body was affected by $CO_2$ concentration. It increased after putting the lid on the bottle.

• Food Science and Preservation
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• v.22 no.3
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• pp.392-398
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• 2015

The physicochemical properties of spray-dried rice flour with Lactobacillus plantarum CGKW3 were investigated. Amylose and damaged starch contents of spray-dried rice flour (S10, S20, S30, and S50) with L. plantarum CGKW3 were 14.18~17.75% and 24.65~34.08%, respectively. The particle size of spray-dried rice flour was $82.28{\sim}131.17{\mu}m$. The rice flour with L. plantarum CGKW3 showed a good powder flowability. The water absorption and water solubility of spray-dried rice flour were 1.96~2.13 and 9.91~21.95%, respectively. Thermal properties measured by differential scanning calorimeter revealed that the enthalpy (${\Delta}H$) for starch gelatinization were highest in the rice flour (S50) with L. plantarum CGKW3. When compared, the viable cell number of spray-dried rice flour were found to be in the following order: S10 (5.78 log CFU/g) < S20 (6.38 log CFU/g) < S30 (6.69 log CFU/g) < S50 (7.11 log CFU/g). The survaival rate of L. plantarum CGKW3 was 60.02-73.85%, which reflected the improvement in the quality of rice flour with an increase in treatment concentration. Based on our results, spray-dried rice flour with L. plantarum CGKW3 could be used in various types of rice foods.