• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.11
• /
• pp.3340-3353
• /
• 2009

This paper aims to study the effect of academia-industrial cooperation on the technical innovation of small and medium-sized companies. A survey was conducted on about 1,100 businesses located in the Sihwa-Banwol industrial estate to analyze the consequence of three factors of academia-industrial cooperation. the joint use of equipments, technological support of universities to businesses, and cooperative technological development through technical guidance-on entrepreneurial capability and their knowledge-absorption ability, and ultimately on their technological innovation,. The validity of the survey result was tested through the Structural Equation Model. On the basis of the comparison between companies which have participated in academy-industry cooperation and companies which have not, this paper suggests that venture businesses should take advantage of the cooperation with universities to boost their competitiveness. The analysis of the three individual factors of the academy-industry cooperation based on the Structural Equation Model shows that all of them have remarkable influence on entrepreneurial capability, but that they don't have as much impact on businesses' knowledge absorption ability. However, the outcome of technological innovation of businesses is primarily influenced by entrepreneurial capability rather than their knowledge absorption ability. The survey also shows that the three factors of the cooperation have an equal impact on the competitiveness of companies regardless of their business type or their products' growth stages. As the companies involved in academy industry cooperation outweigh other businesses, in terms of technological innovation, the numbers of new product development, and the numbers of their process improvement cases, this paper argues that new strategies should be taken for the businesses to fully take advantage of academy-industry cooperation.

• Applied Microscopy
• /
• v.40 no.2
• /
• pp.89-99
• /
• 2010

Fibroblasts are the most common cells in connective tissue and are responsible for the synthesis of extracellular matrix components. The fibrosis associated with chronic inflammation and injury may contribute to cholangiocarcinoma pathogenesis, particularly through an increase in extracellular matrix components, which participate in the regulation of bile duct differentiation during development. Mitochondria produce ATP through oxidative metabolism to provide energy to the cell under physiological conditions. Also, mitochondrial dysfunction and oxidative stress have been implicated in cellular senescence and aging. Alternations in mitochondrial structure and function are early events of programmed cell death or apoptosis and mitochondria appear to be a central regulator of apoptosis in most somatic cell. Clonorchis sinensis, one of the most important parasite of the human bile duct in East Asia, arouses epithelial hyperplasia and ductal fibrosis. Isolated fibroblast from the bile ducts of rats infected by C. sinensis showed increase of cytoplasmic process. In addition, decrease of cellular proliferation was observed in fibroblasts which was isolated from normal rat bile duct and then cultured in media containing C. sinensis excretory-secretory product. However, the effects of C. sinensis infection on the mitochondrial enzyme distribution is not clearly reported yet. Therefore, we investigated the structural change of C. sinensis infected bile duct and mitochondrial enzyme distribution of the cultured fibroblast isolated from the C. sinensis infected rat bile duct. As a result, C. sinensis infected SD rat bile ducts showed the features of chronic clonorchiasis, such as ductal connective and epithelial tissue dilatation, or ductal fibrosis. In addition, fibroblast in ductal connective tissue was damaged by physical effect of fibrotic tissue and chemical stimulation. Immunohistochemically detected mitochondrial electron transferase (ATPase, COXII, Porin) was decreased in C. sinensis infected rat bile duct and cultured fibroblast from infected rat bile duct. It can be hypothesized that the reason why number of electron transferase decrease in fibroblast isolated from the rat bile duct infected with C. sinensis is because dysfunction of electron transport system is occurred mitochondrial dysfunction, increase of ROS (reactive oxygen species) and apoptosis after chemical damage on the cell caused by C. sinensis infection. Overall, C. sinensis infection induces fibrotic change of ductal connective tissue, mutation of cellular metabolism in fibroblast and mitochondrial dysfunction. Consequently, ductal fibrosis inhibits fibroblast proliferation and decreases mitochondrial electron transferase on fibroblast cytoplasm. It was assumed that the structure of bile duct could not normalized and ductal fibrosis was maintained for a long period of time according to fibroblast metamorphosis and death induced by mitochondrial dysfunction.

• Journal of Life Science
• /
• v.27 no.2
• /
• pp.217-224
• /
• 2017

Carbon monoxide (CO), a reaction product of cytoprotective enzyme heme oxygenase-1 (HO-1), is a gaseous messenger with anti-proliferative, anti-apoptotic, and anti-inflammatory actions in many cell types. Here, we investigated the role of CO on the process of monocyte differentiation induced by phorbol 12-myristate 13-acetate (PMA) in human monocytic THP-1 cells. CORM-2 (tricarbonyldichlororuthenium (II) dimer, $Ru2Cl_4(CO)_6$), a CO-releasing compound, decreased a marked cell adherence with a slight reduction of proliferation in monocytic THP-1 cells treated with PMA. And, CORM-2 significantly inhibited expression of differentiation markers such as CD14, CD11b plus CD18 (macrophage-1 antigen, Mac-1 or complement receptor 3, CR3) and phagocytosis of carboxylate-modified red fluorescent latex beads, in PMA-stimulated THP-1 cells. For the further experiments, differentiation of PMA-treated cells was enhanced after the initial 2 days stimulus by removing the PMA-containing media then incubating the cells in fresh media for a another 4 days. And, we observed the secretion of inflammatory cytokines and phagocytosis in differentiated macrophages. Treatment with CORM-2 significantly abolished the secretion of IL-6, $TNF-{\alpha}$ and phagocytosis using fluorescence-conjugated E. coli (K-12 strain) bioparticles in lipopolysaccharide (LPS)-stimulated differentiated macrophages. In conclusion, these results suggest that CO inhibits the differentiation of monocytic THP-1 cells as well as the activation of differentiated macrophages.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.7
• /
• pp.779-789
• /
• 2017

The effects of orally administered Seomaeyakssuk (Artemisia argyi H.) vinegar on lipid metabolism in Sprague-Dawley rats fed a high-fat and high-cholesterol (HFC) diet were analyzed. The experimental animals were divided into five groups: a normal diet group (normal, N), HFC diet group (control, C), HFC diet with lovastatin at 20 mg/kg body weight (B.W.) group (positive control, PC), HFC diet with malt vinegar group (TM), and HFC diet with Seomaeyaksuk vinegar group (TS) (2 mL/kg B.W.). After 4 weeks of feeding rats the experimental diet, contents of serum total lipids and total cholesterol levels of TM and TS groups were significantly lower than those of the PC group. Triglyceride contents of the TM and TS groups were not significantly different from those of the PC group but significantly lower than those of the C group. Content of serum high density lipoprotein-cholesterol was significantly lower than that of the N group but higher than that of the C group. Low density lipoprotein-cholesterol content of serum was 190.68 mg/dL in the TS group, which was the lowest except for the N group. Aspartate transaminase and albumin transaminase activities as a measurement of liver damage index were not significantly different between the TM, TS, and C groups. Serum thiobarbituric acid reactive substance content of the TS group was reduced to a similar level as the N group but was lower than that of the C group in the liver and significantly higher than that of the N group. Antioxidant activity of the TS group was 55.69% in serum, which was a similar to that of the N group, and was 52.39% in the liver, which was not significantly different than that of the C group. From these results, we conclude that Seomaeyakssuk vinegar improves serum lipid content as a result of the complex action of vinegar, an active ingredient of Seomaeyakssuk and a product of the fermentation process.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.27 no.5
• /
• pp.373-384
• /
• 2001

Cellular proliferation is an intricately regulated process mediated by the coordinated interactions of critical growth control genes. Two of these factors in mammalian cells are the p53 and mdm-2 genes. A protein product of the mem-2 oncogene has been recently shown to associate with the protein encoded by the tumor suppressor gene p53. The p53 tumor suppressor protein is stabilized in response to DNA damage and other stress signals and causes the cell to undergo growth arrest or apoptosis, thus preventing the establishment of mutations in future cellular generations. Mutation or loss of p53 is a very common event in tumor progression. It occurs in about 50% of all tumors analysed including of colon, lung, breast and liver. The cellular mdm-2 gene, which has potential transforming activity that can be activated by overexpression, is amplified in a significant percentage of human sarcoma and in other mammalian tumors. Proteins encoded by the mdm-2 gene are able to bind to the p53 protein and, when overexpressed, can inhibit p53's transcriptional activation function, thus mdm-2 can act as a negative regulator of p53 function. Experimental study was performed to observe the relationship between p53 gene mutation and mdm-2 protein expression and apply the results to the clinical activity. 36 golden syrian hamster each weighing $60{\sim}80g$ were used and painted with 0.5% DMBA by 3 times weekly on the right buccal cheek(experimental side) for 6, 8, 10, 12, 14 and 16 weeks. Left buccal cheek(control side) was treated with mineral oil as the same manner to the right side. The hamsters were sacrificed on the 6, 8, 10, 12, 14 & 16 weeks. Normal and tumor tissues from paraffin block were examined for histology and immunohistochemistry observation, and were completely dissected by microdissection and DNA from both tissue were isolated by proteins K/phenol/chloroform extraction. Segments of the hamster p53 exons 5, 6, 7 and 8 were amplified by PCR using the oligonucleotide primers, and then confirmational change was observed by SSCP respectively. The results were as follows : 1. Dysplasia at 6 weeks, carcinoma in situ at 8 weeks and invasive carcinoma from 10 weeks could be observed in experimental groups. 2. p53 mutations were detected in 10 of the 36(28%) and the exons 6(6 of the 10 : 60%) was the most hot spot area among the highy conserved region(exons 5, 6, 7 & 8). 3. Immunohistochemical study confirmed 22 of the 36(61%) of p53 expression involving 10 of p53 mutations. 4. mdm-2 expression of was showed in 3 of the 36(8%) involving 1 of the 22 of p53 expression and 2 of the 14 of p53 non-expression. From the above results, mutation of p53 gene or expression of p53 protein may have the influence of the DMBA induced carcinoma of hamster buccal pouch but the expression of mdm-2 protein may not have relationship with tumorigenesis.

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.4
• /
• pp.397-405
• /
• 2009

In this study, we investigated the potential of producing bioethanol from Liriodendron tulipifera by using oxalic acid pretreatment. Amounts of fermentable sugars, mostly xylose and glucose, in the liquid fraction (hydrolysate) was $40.22g/{\ell}$ after the biomass was pretreated with 0.037 g/g of oxalic acid for 20 minutes at $160^{\circ}C$. Production amounts of ethanol was $8.6g/{\ell}$ from the 72 hours of simultaneous saccharification and fermentation (SSF) on solid fraction of the pretreated sample. At the same condition, when the reaction time increased to 40 minutes, $32.66g/{\ell}$ of fermentable sugars in the hydrolysate and $9.5g/{\ell}$ of ethanol was produced from the process of pretreatment and SSF. As a result of analyzing the fermentation inhibitors, such as acetic acid, 5-HMF, furfural and total phenolic compounds, as the reaction time increased, the amount of the fermentation inhibitors in the hydrolysate increased. Production of the fermentation inhibitors was more affected by initial concentration of oxalic acid rather than reaction time. $3.39{\sim}5.78g/{\ell}$ of acetic acid was produced by pretreatment with 0.013 g/g of oxalic acid, and the amount of furfural produced by decomposition of xylose was 2~3 times higher than the amount of 5-HMF produced by decomposition of glucose. All the hydrolysates contained more than $5g/{\ell}$ of total phenols considered as the degradation product of lignin. Therefore, by analyzing the amount of fermentable sugars and fermentation inhibitors in the hydrolysate, and producing ethanol from SSF of solid fraction of the pretreated sample, the biomass pretreated with 0.037 g/g of oxalic acid for 20 minutes at $160^{\circ}C$ can be expected to produce the most ethanol.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.3
• /
• pp.329-336
• /
• 2006

Iron manufacturing process involves production of various by-product including slag, sludge, sintering and EAF(Electric Arc furnace dust). Some of the by-products such as EAF and sintering dust are disposed of as waste due to their high heavy metal contents. It has been notice for many years that the EAF dust also contain about 65% of Fe(0) and Fe(II) and then the possible utilization of the iron. One possibility is to apply the EAF as a lining material in conjunction with clay or HDPE liners, in waste landfill. The probable reaction between the leachate containing toxic elements such as TCE, PCE dioxine and $Cr^{6+}$ is reduction of the toxic materials in corresponding to the oxidation of the reduced iron and therefore diminishing the toxicity of the leachate. It is, however, prerequisite to evaluate the leaching characteristics of the EAF dust before application. Amelioration of the leachate would be archived only when the level of toxic elements in the treated leachate is less than that of in the untreated leachate. Several leaching techniques were selected to cover different conditions and variable environments including time, pH and contact method. The testing methods include availability test, pH-stat test and continuous column test. Cr and Zn are potentially leachable elements among the trace metals. The pH of the EAF dust is highly alkaline, recording around 12 and Zn is unlikely to be leached under the condition. On the contrary Cr is more leachable under alkaline environment. However, the released Cr should be reduced to $Cr^{3+}$ and then removed as $Cr(OH)_3$. Removal of the Cr is observed in the column test and further study on the specific reaction of Cr and EAF dust is underway.

• The Korean Journal of Air & Space Law and Policy
• /
• v.28 no.2
• /
• pp.183-221
• /
• 2013

While in the early stages of space activities only a few states engaged in the use of outer space, as is well known, commercial space activities have grown dramatically in recent years. Both states, state institutions, and international governmental organizations as well as many private enterprises are engaged in such commercial use of outer space by now. This development is not reflected in the present state of space law. The existing international instruments of space law were developed and finalized before this development and thus only provide very few and sometimes unfitting provisions for the commercial use of outer space and particularly the use by private enterprises. Law formulated in an era when the word "privatization" had not even been coined cannot contain potential problems caused by the increasing commercialization of outer space. For the promotion and further development of such commercial use of outer space it is necessary to clarify and establish the legal framework for such use, because participants will need this information for their future investments in this field. The purpose of this paper is to research and make an analysis of the contents and international regulation of international space commerce, which is rapidly proliferating and to review the process of improvement on national legislations relating to the commercialization of outer space in a few main space advanced countries to make the sustainable progress of commercial space activities project in international society. The legal implications of matters such as international commercial launch services, the liability aspects of such services, intellectual property rights, insurance, product liability insurance and materials processing could one day will be subject to regulated by international space law as well as domestic law. In fact, the question of commercialization is linked to the question of sharing benefits of space activities, and this currently is an agenda item in the Legal Subcommittee of UN COPUOS. Most of developed countries have enacted the national legislation for commercial space activities relating to the development of our space as follows : The National Aeronautic and Space Act of 1958 and the Commercial Space Act of 1998 in the United States, Outer Space Act of 1986 in England, Establishment Act of National Space Center of 1961 in France, Canadian Space Agency Act of 1990 in Canada, Space Basic Act of 2008 in Japan, and Law on Space Activity of 1993 in Russia. Becides there are currently three national legislations relating to space development and commercial space activities in Korea as follows : Aerospace Industry Development Promotion Act of 1987, Outer Space Development Promotion Act of 2005, Outer Space Damage Compensation Act of 2008. Commercial space great promise for the utilization and expansion of human outer space activities but aspring commercial actors must recognize that foreign policy, as well as obligations to the international community as a whole, ensure that commercial space activities will not operate in a legal and regulatory vacuum. As commercial space matures the law and accompanying regulation will most certainly evolve and choose to become participants in the inevitable evolution of law and regulation.

• Journal of the Korean Geotechnical Society
• /
• v.15 no.2
• /
• pp.43-71
• /
• 1999

This research is an experimental work of developing a construction material using municipal wastewater sludge as liner and cover materials for waste disposal landfill. Weathered granite soil and flyash, produced as a by-product in the power plant, were used as the primary additives to improve geotechnical engineering properties of sludge. For secondary additives, bentonite and cement were mixed with sludge to decrease the permeability and to increase the shear strength, respectively. Various laboratory test required to evaluate the design criteria for liner and cover materials, were carried out by changing the mixing ratio of sludge with the additives. Basic soil properties such as specific gravity, grain size distribution, liquid and plastic limits were measured to analyze their effects on permeability, compaction, compressibility and shear strength properties of mixtures. Laboratory compaction tests were conducted to find the maximum dry densities and the optimum moisture contents of mixtures, and their effectiveness of compaction in field was consequently evaluated. Permeability tests of variable heads with compacted samples, and the stress-controlled consolidation tests with measuring permeabilities of samples during consolidation process were performed to obtain permeability, and to find the compressibility as well as consolidational coefficients of mixtures, respectively. To evaluate the long term stability of sludges, creep tests were also conducted in parallel with permeability tests of variable heads. On the other hand, for the compacted sludge decomposed for a month, permeability tests were carried out to investigate the effect of decomposition of organic matters in sludges on its permeability. Direct shear tests were performed to evaluate the shear strength parameters of mixed sludge with weathered granite, flyash and bentonite. For the mixture of sludge with cement, unconfined compression tests were carried out to find their strength with varying mixing ratio and curing time. On the other hand, CBR tests for compacted specimen were also conducted to evaluate the trafficability of mixtures. Various test results with mixtures were assessed to evaluate whether their properties meet the requirements as liner and cover materials in waste disposal landfill.

• Journal of the Korean Vacuum Society
• /
• v.18 no.1
• /
• pp.66-72
• /
• 2009

The detection methods are required to monitor and diagnose the abnormality on the insulation condition inside a gas-insulated switchgear (GIS). Due to a good sensitivity to the products decomposed by partial discharges (PDs) in $SF_6$ gas, the development of a SWNT gas sensor is actively in progress. However, a few numerical studies on the diffusion mechanism of the $SF_6$ decomposition products by PD have been reported. In this study, we modeled $SF_6$ decomposition process in a chamber by calculating temperature, pressure and concentration of the decomposition products by using a commercial CFD program in conjunction with experimental data. It was assumed that the mass production rate and the generation temperature of the decomposition products were $5.04{\times}10^{-10}$ [g/s] and over 773 K respectively. To calculate the concentration equation, the Schmidt number was specified to get the diffusion coefficient functioned by viscosity and density of $SF_6$ gas instead rather than setting it directly. The results showed that the drive potential is governed mainly by the gradient of the decomposition concentration. A lower concentration of the decomposition products was observed as the sensors were placed more away from the discharge region. Also, the concentration increased by increasing the discharge time. By installing multiple sensors the location of PD is expected to be identified by monitoring the response time of the sensors, and the information should be very useful for the diagnosis and maintenance of GIS.