• Journal of the Korean Applied Science and Technology
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• v.6 no.2
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• pp.1-9
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• 1989

• YAKHAK HOEJI
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• v.15 no.3_4
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• pp.87-92
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• 1971

Fourteen novel N,N'-disubstitued thiourea derivatives were synthesized by Hugershof reaction. Antitubercular activities of ten compounds against Mycobacterium tuberculosis H$_{37}$ Rv were tested and was found tat 1-cyclohexyl-3-(4-benzenesulfonepiperidide)-2-thiourea was considerably active at 1mg/ml and 1-$\alpha$-naphthyl-3-(4-benzenesulfonepiperidide)-2-thiourea was slightly active at 1mg/ml. Antibacterial activity of the newly synthesized compounds against E. coli, Sta. aureus and Streptococcus hemolyticus were also tested. 1-cyclohexyl-3-(4-benzenesulfonepiperidide)-2-thiourea was makedly active against E. coli, Sta, aureus and Streptococcus hemolyticus; Phenol coefficients against E. coli, Sta, aureus and Streptococcus hemolyticus were 30,17.5 and 21.3, respectively. 1,1'-p-phenylene-3,3'bis[N-(2-thiazolyl)-sulfamylphenyl]-2,2'-dithiourea and 1-$\alpha$-naphthyl-3-(4-benzenesulfonepiperidide)-2-thiourea were considerably active against E. coli: phenol coefficients, 18.8 and 37.5 respectively. 1-(4-ethoxyphenyl)3-(4-sulfamylphenyl)-2-thiourea was active against Streptococcus hemolyticus: phenol coefficients, 22.5. 1-$\alpha$-naphthyl-3-(4-sulfamylphenyl)-2-thiourea, 1-$\betha$-naphthyl-3-[4-N-(2-thiazolyl)-sulfamylphenyl]-2-thiourea and 1-$\alpha$-naphthyl-3-(4-benzenesulfonepiperidide)-2-thiourea were active against Sta. aureus: phenol coefficients, 17.5, 20.0 and 18.8 respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.799-804
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• 2013

The sensor/actuator active sensor diagnostics procedure, where the sensors/actuators are confirmed to be functioning properly during operation, is a critical component to successfully complete the structural health monitoring (SHM) process with large numbers of active sensors typically installed in a structure. The basis of this process is to track the changes in the capacitive value of piezoelectric materials, which shows up in measured admittance. Due to the temperature dependent nature of piezoelectric materials, we investigated the effects of temperature variations on sensor diagnostic process. The effect of temperature variations found to be remarkable, modifying the measured capacitive values significantly. In addition we analyzed the effect of bonding agents between a PZT patch and a host structure. This paper summarizes considerations needed to develop such sensor diagnostic processes, experimental procedures and results, and additional issues that can be used as guidelines for future investigations.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.5
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• pp.282-292
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• 2003

Several agents are in use to promote new bone formation during bone graft procedures in maxillofacial region. Among them, we have used crude BMP, PRP, and P-15 for experimentally created defects with accompanying graft materials in the rabbit model. The aim of this study is to analyze the effect of above mentioned agents on bone formation using histologic and histomorphometrical methods, thus to provide experimental support for clinical application of these agents. Six rabbits were used as experimental animals. Four surgical defects were created on the distal femoral heads of each animal using trephine drill. The defects were filled with each agents with accompaning graft materials as experimental groups and particulate corti-co-cancellous autogenous graft as control. For histomorphometric analysis, fluorescent dye was injected at 2week and 1week before sacrifice. Then, the animals were sacrificed at 2, 4 and 8weeks after surgery and histologic and histomorphometric examinations were achieved. At two weeks after bone graft, bone formation and active remodeling process were examined in all experimental groups and the control. But the intensity of such activities of the experiments were somewhat weaker than that of the control. In BMP group, the amount of newly formed osteoid was increased constantly and the amount was preserved constantly in PRP group. But in P-15 group, the amount of newly formed osteoid was decreased with time to 8week after surgery. Histologic findings showed superior bony quantity and quality in PRP group than that of P-15 group. MAR(Mineralization Apposition Rate) of all experimental groups were slower than that of control group. In P-15 group, constant foreign body reaction was observed at all periods and the graft material showed inwardly destroyed characteristics rather to mature. The data from this study provide the basis for future studies for evaluating the long-term remodeling process and foreign body reactions observed in P-15 group and clinical study for predictable use of these agents.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.4
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• pp.411-422
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• 2002

Recently, there have been active researches about the VPCS (Virtual Parallel Computing System) based on multiple agents. The PVCS uses personal computers or workstations that are dispersed all over the internet, rather than a high-cost supercomputer, to solve complex problems that require a huge number of calculations. It can be made up with either homogeneous or heterogeneous computers, depending on resources available on the internet. In this paper, we propose a new method in order to distribute worker agents and work packages efficiently on the VPCS based on the IBM Aglets. The previous methods use mainly the master-slave pattern for distributing worker agents and work packages. However, in these methods the workload increases dramatically at the central master as the number of agents increases. As a solution to this problem, our method appoints worker agents to distribute worker agents and workload packages. The proposed method is evaluated in several ways on the VPCS, and its results are improved to be worthy of close attention as compared with the previous ones.

• Applied Biological Chemistry
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• v.46 no.4
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• pp.280-284
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• 2003

To develope of diagnosis and estimation system for utility of fungicides and insecticides as crop protection agents, various 10 physicochemical parameters, hydrophobicity (LogP), dipole moment (DM), HOMO energy, LUMO energy, molar refractivity $(MR:\;cm^3/mol)$, polarizability $(Pol:\;A^3)$, van der Waals molecular surface area $(A^2)$, van der Waals molecular volume $(Vol:\;cm^3)$, molecular weight (amu), hydration energy (Kcal/mol) for the active ingredients of 133 fungicides and 152 insecticides were calculated. And then the distribution ranges for each of the physicochemical parameters in fungicides, sterol biosynthesis inhibitors (DMI: demethylation inhibitor), insecticides and acetylcholine esterase inhibitors (AChE) were confirmed. It is suggested that the various compounds based on the range of the physicochemical parametes could be predicted for possibilities as fungicides and insecticides.

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.47-51
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• 2004

Drug resistance is one of the most significant impediments to successful chemotherapy of cancer. Multidrug-resistance Is characterized by decreased cellular sensitivity to anticancer agents due to the overexpression of P-glycoprotein. By using adriamycin-resistance CL02 cancer cells, we undertook the screening fur agents which were effective to multidrug-resistant cancer cells from strains of the species Sorangium cellulosum isolated in our laboratory. Sorangium cellulose, cellulose-degrading myxobacteria have recently proved to be a rich source of novel anticancer agents. One of the significant examples is the promising anticancer agent epothilone. JW 1006 is the first strain of Sorangium cellulosum which was selected by us for the isolation of a metabolite by a biological screening because of a high cytotoxic activity against the CL02 cancer cells. Cytotoxicity-guided chromatographic fractionation of the culture broth led to the Isolation of two active principles, disorazole $A_1$ and $A_2$. They showed potent cytotoxicity against CL02 cancer cells with $IC_{50}$ values in the picomolar range, and were as active against drug-resistant cancer cells CL02 and CP70 as against the corresponding sensitive cells.

• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1706-1712
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• 2006

Because of the need for new antimicrobial substances with novel mechanisms of action, we report here the use of an Acinetobacter reporter system for high-throughput screening of active antimicrobial agents. The bioreporter Acinetobacter strain DF4/PUTK2 carrying luciferase genes luxCDABE was chosen because of its ecological importance and it is widespread in nature. This bioreporter is genetically engineered to emit light constitutively that can be measured in real time by luminometry. Hence, this reporter system was employed to determine the bacteriostatic actions of spent-culture supernatants derived from twelve bacterial isolates. Out of the results, the strongest bioluminescence inhibitory effect of the supernatants was recorded with Bacillus cereus strain BAC (S5). Subsequently, ethyl acetate extracts of extracellular products of strain BAC (S5) were separated by a thin-layer chromatography (TLC). Based on the bioluminescence inhibitory assay, three fractions were found to have antimicrobial activity. One fraction (C) having the strongest antimicrobial activity was further purified using TLC and characterized by IR, $^1H$ NMR, mass spectrometry, SDS-PAGE, and amino acid composition analysis. The results predicted the presence of 2-pyrrolidone-S-carboxylic acid (PCA) and the octadeconic-acid-like fatty acid. Fraction C also demonstrated a broad inhibitory activity on several Gram-negative and Gram-positive bacteria. In conclusion, the Acinetobacter reporter system shows great potential to be a reliable, sensitive, and real-time indicator of the bacteriostatic actions of the antimicrobial agents.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.2
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• pp.455-459
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• 2006

The inhibitors of prostaglandin $E_2\;(PGE_2)$ production and cyclooxygenase-2 (COX-2) activity have been considered as potential anti-inflammatory agents. In this study, we evaluated 9 compounds isolated from 5 Korean phytomedicinal plants (Spirea prunifolia, Paeonia suffruticosa, Salvia miltiorrhiza, Scutellaria baicalensis, and Artemisia capillaris) for the inhibition of $PGE_2$production and COX-2 expession in lipopolysaccharide (LPS)-stimulated human macrophages U937 cells. As a result, several compound such as prunioside A, penta-O-galloyl-beta-D-glucose, tanshinone IIA, baicalin, baicalein, wogonin, scopolatin, scoparone and decursinol showed potent inhibition of $PGE_2$production (50-70% inhibition at the test concentration of $10\;{\mu}M$). In addition, these compounds were also considered as potential inhibitors of COX-2 activity (45-73% inhibition at the test concentration of $10\;{\mu}M$). These active compound mediating COX-2 inhibitory activities are warranted for further elucidation of active principles for development of anti-inflammatory agents and these properties may contribute to the anti-atopic dermatitis activity.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.16 no.1
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• pp.94-99
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• 2003

Objectives : Gram-positive bacteria have became increasing resistant to antibacterial agents, and hence multi-drug-resistant bacterial pathogens are now a major problem in clinical medicine. There is, therefore, a need for new antibacterial agents. In the course of our screening program for potent antibacterial agent from medicinal plants, the extract of Salvia miltiorrhiza (S. miltiorrhiza) showed antibacterial activity against methcillin resistant Staphylococcus aureus (MRSA) and antibiotic-resistant S. aureus. Methods : S. miltiorrhiza was extracted with 80$\%$ EtOH. The extract was suspended in H2O and fractionated successively with hexane chloroform, ethyl acetate, and n-buthanol. The chloroform fraction, which showed the highest antibacterial activity(MICs, 78㎍/ml) against MRSA, was chromatographed on a silica gel column and recycling prep-LC to give the pure antibacterial component. Results and Conclusions : The second fraction among the chloroform soluble portion of an aqueous EtOH extract of S. miltiorrhiza root showed outstanding antibacterial activity against MRSA and antibiotic-resistant S. aureus compared to the other fraction. An active compound was isolated from the second fraction using silica gel column chromatoraphy and recycling prep-LC. Based on these data together with the IH-, 13C-NMR, mass and mp, the active compounds were identified tanshinone Ⅰ, dehydrotanshinone Ⅰ and cryptotanshinone. Among tanshinones, cryptotanshinone and dihydrotanshinone Ⅰ MICs against MRSA and antibiotics-resistant S. aureus were 12.5, 12.5 and 6.3㎍/ml, respectively.