• YAKHAK HOEJI
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• v.46 no.6
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• pp.392-397
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• 2002

A simple and sensitive high performance liquid chromatographic method to quantitate ursodeoxycholic acid in crude drug pharmaceuticals was investigated. Ursodeoxycholic acid react with 2-bromoacetyl-6-methoxynaphthalene (Br-AMN) in the presence of triethylamine to form highly fluorescent derivative. The derivatization procedure was performed at 7$0^{\circ}C$ and completed within 30 min. The optimal wavelength of the fluorescence detector are λ$_{ex}$=300 nm and λ$_{em}$ = 460 nm. The LOD of the ursodeoxycholic acid was 25 ng/mι based on the S/N =3, and the LOQ was 80 ng/mι based on S/N = 10. Crude drug pharmaceuticals pretreated by solid phase extraction (Sep-pak $C_{18}$ cartridge) which were shown very good separation and recovery values for the compound.d.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.275-282
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• 1998

In this paper, we designed and fabricated 5-stage microwave solid state power amplifier using balanced amplifier scheme for X-band electronic radar reflector. The used substrate is FR4 and the used active devices are FHX35LC, FLK012WF and FLK022WG. The circuit design and optimization had been carried out through the microwave CAD program CNL2 The measured values show 46dB in gain, input return loss -14.2dB, output return loss -16.6dB and IM3 is 32dBc at designed bandwidth. The measured results are almost agreed with the simulated values.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.183-191
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• 2010

The phase changes of 1-palmitoyl-$d_{31}$-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC_$d_{31}$) bilayers distorted by an antimicrobial peptide, a magainin 2 or an aurein 3.3 were investigated by using $^2H$ solid-state NMR (SSNMR) spectroscopy. From the theoretical simulation of the experimental $^2H$ solid-state NMR spectra the geometric structure constants and the lateral diffusion coefficients were obtained in the peptide-lipid mixture phases. Within five days of the peptide action on the lipid bilayers only the distorted alignment of the bilayers were measured but after 100 days an elliptic toroidal pore structure and an inverted hexagonal phase were formed in the presence of magainin 2 and aurein 3.3, respectively. In order to investigate the effect of an anionic lipid molecule on the actions of two peptides on the lipid bilayer, the same experiments were performed on the POPC_$d_{31}$/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG) bilayer and the significant differences in the actions of two peptides on two bilayers of POPC_$d_{31}$ and POPC_$d_{31}$/POPG were measured.

• Journal of Surface Science and Engineering
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• v.39 no.2
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• pp.70-75
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• 2006

As technology advances, there is a demand for development of hard, solid lubricant coating. (Ti,Cr)N-$MoS_2$, films were deposited on SKD 11 tool steel substrate by co-deposition of $MoS_2$, with (Ti,Cr)N using a D.C. magnetron sputtering process. The influence of the $N_2/Ar$ gas ratio, the deposition temperature, the amount of $MoS_2$ in the films, and the bias voltage on the mechanical and the structural properties of the films were investigated. Wear tests were performed on the films deposited in various conditions.

• The Journal of the Korean Society for Microbiology
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• v.20 no.1
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• pp.91-102
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• 1985

The advantages of enzyme-linked immunosorbent assay(ELISA) are its senstivity and simplicity in detecting IgG, IgM and IgA antibody. To apply ELISA to diagnosis of typhoid fever, antigen such as lipopolysaccharide of Salmonella typhi or killed whole cell must be coated on solid phase. It is easy to coat lipopolysaccharide on ELISA plate but troublesome to purify it. As it is easy to obtain the killed whole cells, the development of the appropriate method by which those antigens of S. typhi are optimally coated on solid phase is needed. To establish the appropriate method, carbonate buffer, methanol or poly-L-lysine was applied as binding substance on polystyrene or polyvinylchloride plate as solid phase when the killed whole cell antigens of S. typhi varided as follows: $10^6$, $10^7$, $10^8$ and $10^9\;cell/ml$. The criteria of the optimal method were determined as follows: 1. The optical density of positive sera is above 1.0(0.6 in IgM) at 1:10 serum dilution and is 0.3(0.2 in IgM) higher than that of negative sera: 2. The O.D. of sera is flat or lowering according to serum dilution: 3. It must be that the O.D. of negative sera is lower than 0.2 at the point of serum dilution where the O.D. of positive sera is higher than 1.0(0.5 in IgM). The results obtained were summarized as follows: 1. The methods which fitted the above criteria were to use poly-L-lysine as binding substance, polyvinylchloride plate as solid phase and $10^7\;cell/ml$ as antigen concentration of S. typhi(poly-L-lysine/polyvinylchloride/$10^7$) and poly-L-lysine/polyvinylchloride/$10^8$ in detecting IgG antibody, methanol/polystyrene/$10^9$, poly-L-lysine/polyvinylchloride/$10^8$ and poly-L-lysine/polyvinylchloride/$10^9$ in IgM and carbonate buffer/polystyrene/$10^8$, carbonate buffer/polystyrene/$10^9$, methanol/polystyrene/$10^8$, methanol/polyvinylchloride/$10^8$, methanol/polyvinylchloride/$10^9$, poly-L-lysine/polyvinylchloride/$10^8$ and poly-L-lysine/polyvinylchloride/$10^9$ in IgA. 2. The coaling method using poly-L-lysine, polyvinylchloride plate and $10^8\;cell/ml$ was best to assay IgG, IgM and IgA antibody all in one. By this method, to assay the each immunoglobulin calss with an appropriate fixed serum dilution, 1:320 dilution was best.

• Journal of Chest Surgery
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• v.57 no.2
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• pp.217-219
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• 2024

Matching for the rhesus (Rh) blood group is currently not taken into account in the organ allocation system. However, in Rh-mismatched transplantation, the primary concern is the potential for RhD-negative recipients to develop sensitization and produce anti-D antibodies if they receive a transfusion of RhD-positive blood. It is estimated that over 80% of RhD-negative recipients may experience Rh allosensitization when exposed to RhD-positive blood, although this occurrence is less common in recipients of solid organs. In theory, RhD-negative recipients who receive organs from RhD-positive donors are at risk of alloimmunization and the production of anti-D antibodies, which could complicate future blood product transfusions. However, our understanding of the impact of donor-recipient Rh mismatch on transplant outcomes, particularly in heart transplantation, is limited. We report a case of successful Rh-mismatched heart transplantation, which was effectively managed through the use of preoperative RhD immunoglobulin and plasmapheresis.

• Journal of Web Engineering
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• v.18 no.8
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• pp.837-864
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• 2020

We introduce a new type of 3D text-based CAPTCHA, called DotCHA, which relies on human interaction and overcomes the limitations of existing 2D and 3D CAPTCHAs. DotCHA asks users to rotate a 3D text model to identify the correct letters. The 3D text model is a twisted form of sequential 3D letters around a center pivot axis, and it shows different letters depending on the rotation angle. Because each model consists of many small spheres instead of a solid letter model, DotCHA is classified as a scatter-type CAPTCHA and resists character segmentation attacks. Moreover, DotCHA is resistant to machine learning attacks because each letter is only identified in a particular direction. We demonstrate that DotCHA is resistant to existing types of attacks while maintaining usability.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.1
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• pp.61-70
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• 2012

Feasibility of co-digestion was investigated by a series of anaerobic batch experiments using sewage sludge, swine waste, and food waste leachate as substrates. The organic solid wastes were collected from M city, where the daily productions of sewage sludge, swine waste, and food waste leachate were 178 ton/d, 150 ton/d, and 8 ton/d, respectively. Both swine waste and food waste leachate showed superior methane yields, methane productivities, and organic pollutant removal efficiencies compared to sewage sludge. Co-digestion of the total amounts of organic solid wastes would enhance methane production by 5.60 times $(530\;m^{3}\;CH_{4}/d\;{\rightarrow}\;2,968\;m^{3}\;CH_{4}/d)$. However, it also increase the amount of digestate by 1.88 times with 3.79 to 4.92 times higher pollutants (chemical oxygen demands total nitrogen, and total phosphorus) loading rates. Co-digestion of organic solid wastes is a valid strategy to enhance the performance of an anaerobic sludge digester and the energy independence of a wastewater treatment plant. Anyhow,the increment of digestate with higher pollutant loading would need a careful counterplan in the operation of the main stream of the treatment plant.

• Corrosion Science and Technology
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• v.10 no.2
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• pp.47-51
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• 2011

Main issues in the automotive industry are the reduction of vehicle body weight for energy savings and improvement of crashworthiness for passenger safety. In order to address both these issues, there has recently been increasing application of galvannealed advance high strength steel (GA AHSS) sheets for automobiles. However, GA AHSS sheets have some surface defects such as coating bare spots due to the addition of solid-solution strengthening elements, which result in the deterioration of the galvannealing reaction. In this study, the effects of galvannealed manufacturing conditions on surface and mechanical properties, resistance spot weldability on a laboratory scale, and GA 980 MPa steel sheets produced by commercial continuous galvannealing line (CGL) were investigated.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.6
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• pp.272-279
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• 2015

$Y_2O_3:Eu^{3+}$ is an excellent red-emitting phosphor, which has been widely used for display devices due to highly luminescent property and chemical stability. In this study, $Y_2O_3:Eu^{3+}$ red phosphors were prepared using the solid state reaction and RF thermal plasma synthesis. The particle size of $Y_2O_3:Eu^{3+}$ phosphors obtained by the solid state reaction varied from 10 to $20{\mu}m$, and 30~100 nanometer sized $Y_2O_3:Eu^{3+}$ particles were obtained from a liquid form of raw material through RF thermal plasma synthesis without an additional heat treatment. Photoluminescence measurements of the obtained $Y_2O_3:Eu^{3+}$ particles showed a red emission peak at 611 nm ($^5D_0{\rightarrow}^7F_2$). PL intensity of red nano phosphors prepared by RF thermal plasma synthesis was comparable to that of red phosphors prepared by the solid state reaction, indicating that nano-sized $Y_2O_3:Eu^{3+}$ red phosphors could be successfully synthesized using one-step process of RF thermal plasma.