• Journal of Powder Materials
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• v.23 no.3
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• pp.207-212
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• 2016

In this study, Fe-Cu-Ni-Mo-C low alloy steel powder is consolidated by spark plasma sintering (SPS) process. The internal structure and the surface fracture behavior are studied using field-emission scanning electron microscopy and optical microscopy techniques. The bulk samples are polished and etched in order to observe the internal structure. The sample sintered at $900^{\circ}C$ with holding time of 10 minutes achieves nearly full density of 98.9% while the density of the as-received conventionally sintered product is 90.3%. The fracture microstructures indicate that the sample prepared at $900^{\circ}C$ by the SPS process is hard to break out because of the presence of both grain boundaries and internal particle fractures. Moreover, the lamellar pearlite structure is also observed in this sample. The samples sintered at 1000 and $1100^{\circ}C$ exhibit a large number of tiny particles and pores due to the melting of Cu and aggregation of the alloy elements during the SPS process. The highest hardness value of 296.52 HV is observed for the sample sintered at $900^{\circ}C$ with holding time of 10 minutes.

• Polymer(Korea)
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• v.31 no.6
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• pp.543-549
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• 2007

We synthesized various polyurethanes(PU) haying different hard segments with different molecular weights of the soft segment to explore the effect of structure on the dispersion of silver particle in the phase of synthesized polyurethanes matrix. The thermal stability was increased by increasing the number of aromatic compound, while the degree of dispersion for silver particle was decreased. Silver particles showed better dispersion in the PU matrix having aromatic compounds when the soft segments were held constant. On the contrary, when the hard segment was held constant, silver particles on the PU matrix haying low $M_w$ of soft segment showed better dispersion than high $M_w$ of soft segment because poor chain mobility of low $M_w$ of soft segment restricted re-aggregation of silver particle. A sheet resistance of composite materials showed different aspects. In this case, the inter connection between silver particles was more important than its dispersion. In this study, the NDI-PEG 900/silver particle composite film showed the best thermal stability and electro conductivity.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.3
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• pp.151-173
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• 2006

Purpose : This study was performed to evaluate anti-thrombotic and anti-inflammatory effects of BokbangHongdeungPaejangSan water extract (BHPS). Methods : BHPS was investigated using cultured cells and a murine models. As for the parameters of inflammation, levels of several inflammatory cytokines and chemical mediators which are known to be related to inflammation were determined in mouse lung fibroblast cells (mLFC) and RAW 264.7 cells. Results : In experiment of anti-thrombotic effect, BHPS inhibited the platelet aggregation induced by ADP and epinephrine, and inhibited pulmonary embolism induced by collagen and epinephrine. BHPS increased Platelet number and fibrinogen amount, and shortened PT and APTT in thrombus model induced by dextran. In experiment of anti-inflammatory effect, BHPS inhibited IL-1${\beta}$, IL-6, TNF-${\alpha}$, COX-2 and NOS-II mRNA expression in a concentration-dependent manner in RAW 264.7 cell line, and inhibited significantly NO production at 50, 100 ${\mu}g/ml$, and also inhibited ROS production in a concentration-dependent manner. BHPS inhibited IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production significantly in serum of acute inflammation-induced Balb/c mice, and decreased IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production in spleen tissue, but increased IL-1${\beta}$, IL-6 and TNF-${\alpha}$ production in liver tissue. BHPS increased survival rate at the 3th day in ICR mice with lethal endotoxemia induced by LPS. Conclusion : These results suggest that BHPS can be used for treating diverse female diseases caused by thrombosis and inflammation such as endometriosis, pelvic pain, cervicitis, pelvic inflammatory disease and pelvic tuberculosis and so forth.

• Korean Journal of Microbiology
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• v.13 no.3
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• pp.109-115
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• 1975

DNA's were extracted from Saccharomyces cerevisiae and Mycobacterium phlei and the damaging cell walls of these microoragnisms were examined under an electron microscope in the extraction process in which a number of physico-chemical tratments of cells was involved. While the DNA was easily extracted from S. cerevisiae using conventional meylelded very little DNA, of M. phlei was extremely difficult to isolate and yielded very little DNA, applying various methods of isolation published earlier. When the cell walls of S. cerevisiae were examined with the electron microscope, they were not yet damaged even after the cells were treated with sodium lauryl sulfate(SLS) and ethylene diamine tetracetic acid(EDTA), but they were completely destroyed by the treatment of sodium perchlorate followed by the addition of chloroform and a vigorous agitation. Oozing cytoplasm through the broken cell walls was also observed. In the extraction of DNA from M.phlei, the pronase was not effective at the aerobic environment of the sample. When phenol was applied at the last step of DNA isolation, an extreme damage mass yielding little DNA into the solution. Unlike the cells of S.cerevisiae.M.phlei cells showed a tendency of aggregation, thus the destruction of cell walls by sodium hydroxide was seen only on the walls of peripheral cells in the aggregated mass, leaving the walls of the inner cells undamaged.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.157-161
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• 2009

In recent years, there is a remarkable progress in ICTs (Information and Communication Technologies), and then many attempts to apply ICTs to other industries are being made. In the field of disaster managements, ICTs such as RFID (Radio Frequency IDentification) and USN (Ubiquitous Sensor Network) are used to provide safe environments. Actually, various types of early warning systems using USN are now widely used to monitor natural disasters such as floods, landslides and earthquakes, and also to detect human-caused disasters such as fires, explosions and collapses. These early warning systems issue alarms rapidly when a disaster is detected or an event exceeds prescribed thresholds, and furthermore deliver alarm messages to disaster managers and citizens. In general, these systems consist of a number of various sensors and measure real-time stream data, which requires an efficient and rapid data processing technique. In this study, an event-driven architecture (EDA) is presented to collect event effectively and to provide an alert rapidly. A publish/subscribe event processing method to process simple event is introduced. Additionally, a complex event processing (CEP) technique is introduced to process complex data from various sensors and to provide prompt and reasonable decision supports when many disasters happen simultaneously. A basic concept of CEP technique is presented and the advantages of the technique in disaster management are also discussed. Then, how the main processing methods of CEP such as aggregation, correlation, and filtering can be applied to disaster management is considered. Finally, an example of flood forecasting and early alarm system in which CEP is incorporated is presented It is found that the CEP based on the EDA will provide an efficient early warning method when disaster happens.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.15-21
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• 2009

The goal of wireless sensor networks is to collect sensing data on specific region over wireless communication. Sink node gathers all local sensing data, processes and transmits them to users who use sensor networks. Generally, senor nodes are low-cost, low power devices with limited sensing, computation and wireless communication capabilities. And sensor network applies to multi-hop communication on large-scale network. As neighboring sensor nodes have similar data, clustering is more effective technique for 'data-aggregation'. In cluster formation technique based on multi-hop, it is necessary that the number of cluster member nodes should be distributed equally because of the balance of cluster formation To achieve this, we propose a method to customize cluster member nodes for energy-efficiency in wireless sensor networks.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.3
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• pp.262-267
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• 2006

The objective of this study was to develop new self-organized nanogels as a means of drug delivery in patients with cancer. Pullulan (PUL) and deoxycholic acid (DOCA) were conjugated through an ester linkage between the hydroxyl group in PUL and the carboxyl group in DOCA. Three types of PUL/DOCA conjugates were obtained, differing in the number of DOCA substitutions (DS; 5, 8, or 11) per 100 PUL anhydroglucose units. The physicochemical properties of the resulting nanogels were characterized by dynamic light scattering, transmission electron microscopy, and fluorescence spectroscopy. The mean diameter of DS 11 was the smallest (approx. 100 nm), and the size distribution was unimodal. To determine the organizing behavior of these conjugates, we calculated their critical aggregation concentrations (CACs) in a 0.01-M phosphate buffered saline solution. They were $10.5{\times}10^{-4}mg/mL,\;7.2{\times}10^{-4} mg/mL,\;and\;5.6{\times}10^{-4} mg/mL$ for DS 5, 8, and 11, respectively. This indicates that DOCA can serve as a hydrophobic moiety to create self-organized nanogels. To monitor the drug-releasing behavior of these nanogels, we loaded doxorubicin (DOX) onto the conjugates. The DOX-loading efficiency increased with the degree of DOCA substitution. The release rates of DOX from PUL/DOCA nanogels varied inversely with the DS. We concluded that the PUL/DOCA nanogel has some potential for use as an anticancer drug carrier because of its low CAC and satisfactory drug-loading capacity.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.10
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• pp.1508-1513
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• 2006

Myostatin (MSTN) and insulin-like growth factors (IGFs) are a known inhibitor and stimulators of proliferation and differentiation of muscle cells, respectively. The present study was performed to investigate the relationship of MSTN-induced growth inhibition to expression of the IGF system components and myogenin, a muscle cell-specific transcription factor, in rat L6 myoblasts. The L6 cells transfected with a green fluorescent protein-MSTN plasmid expression construct had a 47% less cell number than mock-transfected cells after 3-d serum-free culture, accompanied by delayed differentiation which was suggested by inhibited aggregation of cells. Moreover, cells transfected with the expression construct had decreased expression of IGF-II and myogenin genes, but not IGF-I or its receptor genes, as examined by reverse transcription-polymerase chain reaction. The reduced mitosis of the L6 cells transfected with the MSTN-expression construct increased following an addition of either IGF-I or IGF-II to the culture medium, but not to the level of mock-transfected cells. By contrast, myogenin gene expression in these cells increased after the addition of either IGF to the level of mock-transfected cells. Collectively, these results suggest that the inhibitory effect of MSTN on L6 cell proliferation and differentiation is likely to be partly mediated by serially suppressed expression of IGF-II and myogenin genes, not IGF-I gene.

• Journal of agricultural medicine and community health
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• v.27 no.1
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• pp.1-8
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• 2002

Pest control is required for protecting the food supply and for controlling disease vectors. Unfortunately, there is no perfectly safe form of pest control. Pesticides are commonly used for pest control. Pesticides are defined under the US Federal Insecticide Fungicide and Rodenticide Act(FIFRA) as any substance or mixture of substances intended to prevent, destroy, repel, or mitigate pests, and any substance or mixture of substances intended for use as a plant regulator, defoliant, or dessicant(40 CFR Part 152). Currently in the United States, there are 890 active ingredients registered as pesticides. Approximately one billion pounds of active ingredient are used in the US per year. Unlike most chemicals(anti-neoplastic and anti-micobial medications are the principal exceptions), pesticides are specifically designed to kill and cause harm. Because society allows these chemicals to be disseminated into the environment, it is important to monitor the health effects associated with these releases. This represents an important justification for establishing and maintaining surveillance systems for acute pesticide-related illness and injury. A comprehensive, national surveillance system for acute pesticide-related illness and injury does not currently exist in the US. Although the United States has several surveillance systems for this condition, none provide a complete understanding of the problem of acute pesticide-related illness and injury. The Toxic Exposure Surveillance System(TESS) and Bureau of Labor Statisitics(BLS) are useful for assessing magnitude and trends. The state-based surveillance systems are more useful for timely identification of outbreaks and emerging problems. Efforts are underway to increase the number of states that conduct surveillance, and to broaden the use of the standardized case definition to facilitate aggregation of data across states. Through such efforts, a comprehensive, national surveillance system may be attainable.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.2
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• pp.125-151
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• 2008

Purpose: In this study, we investigated the anti-thrombotic efficacy of "Eungapbang-gagam(EGB)" currently used in clinical treatment of PID Methods: We studied inhibitory effect of platelet cohesion, suppressive effect of GPIIb/IIIa activity, inhibitory effect of $TXB_2$ and $PGE_2$ biosynthesis, and oxidative damage suppression effects of "EGB" in vitro. Also, suppression of pulmonary embolism and changes of related factors in dextran coagulation condition model were studied in vivo. Results: In this study, EGB extract showed dose-dependent inhibitory effect on platelet coagulation induced by ADP, epinephrine, collagen, arachidonic acid. Also it showed dose-dependent inhibition effect on GPIIb/IIIa activities compared to the control group. EGB extract significantly suppressed the decrease of speed of bloodstream caused by blood coagulation in dextran coagulation condition model and increased the number of platelets and amount of fibrinogen, and decreased the APTT in dextran coagulation condition model compared to the control group. EGB extract showed dose-dependent decrease of oxidative damages caused by DPPH and superoxide anion radicals, whereas dose-dependent increase of superoxide dismutase like activity was observed compared to the control group. Conclusion: We confirmed the anti-thrombosis and anti-oxidative efficacy of "Eungapbang-gagam". Various clinical applications of "Eungapbang-gagam" as well as use of data for the construction of EBM is anticipated.