• Biomolecules & Therapeutics
• /
• v.27 no.6
• /
• pp.577-583
• /
• 2019

Human cytochrome P450 2C9 is a highly polymorphic enzyme that is required for drug and xenobiotic metabolism. Here, we studied eleven P450 2C9 genetic variants-including three novel variants F69S, L310V, and Q324X-that were clinically identified in Korean patients. P450 2C9 variant enzymes were expressed in Escherichia coli and their bicistronic membrane fractions were prepared The CO-binding spectra were obtained for nine enzyme variants, indicating P450 holoenzymes, but not for the M02 (L90P) variant. The M11 (Q324X) variant could not be expressed due to an early nonsense mutation. LC-MS/MS analysis was performed to measure the catalytic activities of the P450 2C9 variants, using diclofenac as a substrate. Steady-state kinetic analysis revealed that the catalytic efficiency of all nine P450 2C9 variants was lower than that of the wild type P450 2C9 enzyme. The M05 (R150L) and M06 (P279T) variants showed high $k_{cat}$ values; however, their $K_m$ values were also high. As the M01 (F69S), M03 (R124Q), M04 (R125H), M08 (I359L), M09 (I359T), and M10 (A477T) variants exhibited higher $K_m$ and lower $k_{cat}$ values than that of the wild type enzyme, their catalytic efficiency decreased by approximately 50-fold compared to the wild type enzyme. Furthermore, the novel variant M07 (L310V) showed lower $k_{cat}$ and $K_m$ values than the wild type enzyme, which resulted in its decreased (80%) catalytic efficiency. The X-ray crystal structure of P450 2C9 revealed the presence of mutations in the residues surrounding the substrate-binding cavity. Functional characterization of these genetic variants can help understand the pharmacogenetic outcomes.

• Journal of Life Science
• /
• v.19 no.4
• /
• pp.442-448
• /
• 2009

We investigated photooxidation and responses of antioxidant enzymes involved in scavenging reactive oxygen species (ROS) after light-chilling ($4^{\circ}C$) for 2 days and post chilling ($25^{\circ}C$) in rice leaves. Chilling leaves indicated a 50% reduction in photosynthetic efficiency ($F_v/F_m$ ratio) and a 48% increase of $H_2O_2$, respectively, compared to the control group. In comparison with the control, activities of superoxide dismutase (SOD) and glutathione reductase (GR) increased at light-chilling and post-chilling. CuZn-SOD and Mn-SOD among SOD forms were detected in rice leaves, while Fe-SOD was not found. The increase of SOD and GR activity may serve as a basis for defense against chilling injury as it dismutase superoxide generated by light-chilling. Catalase (CAT) activity decreased during light-chilling, while activity of APX showed remarkable increase during light-chilling in rice leaves. Among CAT isoforms analyzed by 10% native PAGE, activities of isoform -2 and -3 were inhibited during light-chilling. From the elevated APX activity and decreased CAT activity, we suggest that these two enzymes show mutual supplementary relationships, indicating different tendency during light-chilling.

• Journal of Radiation Protection and Research
• /
• v.24 no.4
• /
• pp.205-213
• /
• 1999

Effective dose conversion coefficients from unit activity radionuclides contaminated on the ground surface were calculated by using MCNP4A rode and male/female anthropomorphic phantoms. The simulation calculations were made for 19 energy points in the range of 40 keV to 10 MeV. The effective doses E resulting from unit source intensity for different energy were compared to the effective dose equivalent $H_E$ of previous studies. Our E values are lower by 30% at low energy than the $H_E$ values given in the Federal Guidance Report of USEPA. The effective dose response functions derived by polynomial fitting of the energy-effective dose relationship are as follows: $f({\varepsilon})[fSv\;m^2]=\;0.0634\;+\;0.727{\varepsilon}-0.0520{\varepsilon}^2+0.00247{\varepsilon}^3,\;where\;{\varepsilon}$ is the gamma energy in MeV. Using the response function and the radionuclide decay data given in ICRP 38, the effective dose conversion coefficients for unit activity contamination on the ground surface were calculated with addition of the skin dose contribution of beta particles determined by use of the DOSEFACTOR code. The conversion coefficients for 90 important radionuclides were evaluated and tabulated. Comparison with the existing data showed that a significant underestimates could be resulted when the old conversion coefficients were used, especially for the nuclides emitting low energy photons or high energy beta particles.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.24 no.1
• /
• pp.37-42
• /
• 2024

This paper suggests polynomial time algorithm for cutwidth minimization problem that classified as NP-complete because the polynomial time algorithm to find the optimal solution has been unknown yet. To find the minimum cutwidth CW_f(G)=max_𝜈∈_VCW_f(𝜈)for given graph G=(V,E),m=｜V｜, n=｜E｜, the proposed algorithm divides neighborhood N_G[𝜈_i] of the maximum degree vertex 𝜈_i in graph G into left and right and decides the vertical cut plane with minimum number of edges pass through the vertex 𝜈_i firstly. Then, we split the left and right N_G[𝜈_i] into horizontal sections with minimum pass through edges. Secondly, the inner-section vertices are connected into line graph and the inter-section lines are connected by one line layout. Finally, we perform the optimization process in order to obtain the minimum cutwidth using vertex moving method. Though the proposed algorithm requires O(n²) time complexity, that can be obtains the optimal solutions for all of various experimental data

• The Korean Journal of Mycology
• /
• v.13 no.1
• /
• pp.1-10
• /
• 1985

This experiment was undertaken to investigate proper conditions for protoplast isolation from strains of Agaricus bisporus, Flammulina velutipes, Lentinus edodes, Pleurotus florida, Pleurotus ostreatus, Pleurotus sajor-caju and Volvariella volvacea. Combination of ${\beta}-D-glucanase$, novozym 234 and snail enzyme with 0.6M $MgSO_4$ in 0.05M Na-maleate buffer, pH 5.8 was the most effective for isolation of protoplasts. High yields of protoplasts were obtained from $4{\sim}5$ days old mycelia of P. florida and P. ostreatus on mushroom complete agar medium. Protoplasts were also obtained in good yield from other fungi but A. bisporus and V. volvacea. In the latter two cases protoplast release was observed; however, the yield was much lower than those of the other fungi.

• Carbon letters
• /
• v.19
• /
• pp.66-71
• /
• 2016

The development of nanostructured functional materials derived from biomass and/or waste is of growing importance for creating sustainable energy-storage systems. In this study, nanoporous carbonaceous materials containing numerous heteroatoms were fabricated from waste coffee grounds using a top-down process via simple heating with KOH. The nanoporous carbon nanosheets exhibited notable material properties such as high specific surface area (1960.1 m² g⁻¹), numerous redox-active heteroatoms (16.1 at% oxygen, 2.7 at% nitrogen, and 1.6 at% sulfur), and high aspect ratios (>100). These unique properties led to good electrochemical performance as supercapacitor electrodes. A specific capacitance of ~438.5 F g⁻¹ was achieved at a scan rate of 2 mV s⁻¹, and a capacitance of 176 F g⁻¹ was maintained at a fast scan rate of 100 mV s⁻¹. Furthermore, cyclic stability was achieved for over 2000 cycles.

• Toxicological Research
• /
• v.14 no.3
• /
• pp.385-391
• /
• 1998

The study was carried out to evaluate the acute toxicity of enrofloxacin-colistin combination via a single oral(p.o.)and intravenous(i.v.) administration in ICR mice. All procedures of the test were performed by the established regulation of Korean National Institute of Safety Research (1994. 4.14). The maximal dose of oral and intravenous routes was 5,000mg/kg and 90mg/kg, consisting with each 6 groups including control of male and female, respectively. As the results, $LD_{50}$m}'s of the combinations showed 3,075mg/kg (f)and 2,564mg/kg(m) after oral administrations, together with 48mg/kg(f) and 40mg/kg(m) after intravenous administration. These facts indicated that acute toxicitiy of enrofloxacin-colistin combination were different depending on the administration routes and sexes in ICR mice. In conclusion, the route of enrofloxacin-colistin combination must not choose as i.v. route administration in terms of acute toxicity based on $LD_{50}$.

• Korean Chemical Engineering Research
• /
• v.48 no.4
• /
• pp.440-443
• /
• 2010

A hybrid supercapacitor consisting of Co-Mn oxide as a cathode, activated carbon as an anode, and 6 M KOH as a electrolyte was fabricated and its supercapacitor performance was investigated by means of cyclic voltammetry. The prepared supercapacitor showed the specific capacitance of 67.3 F/g, energy density of 18.3 Wh/kg, and power density of 237.7 kW/kg, respectively. It means that the supercapacitor can be used for the practical applications.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.8
• /
• pp.824-833
• /
• 2006

In this paper, the image modelling of road's lane markings is established using view frustum(VF) model. From this model, a measurement system of lane markings and obstacles is proposed. The system also involve the real time processing of the 3D position coordinate and the distance data from the camera to the points on the 3D world coordinate by virtue of the camera calibration. In order to reduce their measurement error, an useful algorithm for which analyze the geometric variations due to traveling vehicle's fluctuation using VF model is proposed. In experiments, without correction, for instance, the $0.4^{\circ}$ of pitching rotation gives the error of $0.4{\sim}0.6m$ at the distance of 10m, but the more far distance cause exponentially the more error. We con finned that this algorithm can be reduced less than 0.1m of error at the same condition.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.4
• /
• pp.471-477
• /
• 2008

The porcine PRKAG3 (RN) gene encodes the regulatory gamma subunit of adenosine monophosphate-activated protein kinase (AMPK), which is a good candidate gene affecting meat quality. In this study, the effects of two missense mutations A595G (Ile199Val) and G154A (Gly52Ser) in porcine PRKAG3 gene on meat quality traits were studied in M. Longissimus dorsi (LD), M. Semispinalis capitis (SC) and M. Biceps femoris (BF) from different populations of 326 pigs. The PRKAG3 alleles 199I, 199IV, 52S and 52G were identified with PCR-RFLPs and all genotypes - 199I/199I, 199I/199V, 199V/199V, 52S/52S, 52S/52G and 52G/52G - were found. The frequency of V allele was larger than that of I allele in all populations. I allele frequency was zero in Chinese Meishan pigs (population D) especially. G allele frequency was larger than that of S allele in all populations except Large White (population A). Both variations at the PRKAG3 locus significantly affected these meat quality traits. The pork meat quality has not previously been established in Meishan or crosses thereof. The results suggested that generally pH of LD, SC and BF was higher in Meishan pigs than that in other populations. Moreover, Meishan pigs showed higher water-holding capacity and intramuscular fat (IMF), lower water content and water loss percentage compared to other populations in terms of the two variations. The results present here supply new evidence that alleles V199I and G52S at the PRKAG3 locus affect pork meat quality and provide useful information on pork production.