• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.295-298
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• 2008

Creatine kinase (CK; E.C. 2.7.3.2) is an important enzyme that catalyzes the reversible transfer of a phosphoryl group from ATP to creatine in energy homeostasis. The brain-type cytosolic isoform of creatine kinase (BB-CK), which is found mainly in the brain and retina, is a key enzyme in brain energy metabolism, because high-energy phosphates are transfered through the creatine kinase/phosphocreatine shuttle system. The recombinant human BB-CK protein was overexpressed as a soluble form in Escherichia coli and crystallized at $22^{\circ}C$ using PEG 4000 as a precipitant. Native X-ray diffraction data were collected to $2.2{\AA}$ resolution using synchrotron radiation. The crystals belonged to the tetragonal space group $P4_32_12$, with cell parameters of a=b=97.963, $c=164.312{\AA},\;and\;{\alpha}={\beta}={\gamma}=90^{\circ}$. The asymmetric unit contained two molecules of CK, giving a crystal volume per protein mass $(V_m)$ of $1.80{\AA}^3\;Da^{-1}$ and a solvent content of 31.6%.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.10
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• pp.90-97
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• 1996

A numerical method for scattering of electromagnetic waves from a periodic strip grating over a grounded dielectric slab is considered for TE and TM polarization cases from the viewpoints of both reflection grating problem and leaky wave antenna problem. The analysis is based on a mode expansion method, floquet's theorem, and the method of moments. Numerical results involving some combinations of geometric parameters are presented in terms of complex propagation constant (kd-$\beta$d diagram), radiation pattern, and relative scattered powers of spectral modes. In particular, the relationship between complex propagatio constnat form the viewpoint of leaky wqve antenna problem and Off-bragg and bragg blazing phenomena from the viewpoint of reflecton graing problem is investigated.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1282-1288
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• 2020

In the first study, the Radon emanation and radiological hazards associated with radionuclides in soil samples, collected from 9 various date palm farms located in 3 different districts in Saudi Arabia were determined through a high purity Germanium (HPGe) gamma-ray spectrometer. The estimated average values of Radon emanation coefficient and Radon mass exhalation rate for soil samples were 0.535 ± 0.016 and 50.063 ± 7.901 mBqkg^-1h^-1, respectively. The annual effective dose of radionuclides in all sampling locations was found to be lower than UNSCEAR's recommended level of 0.07 mSvy^-1 for soil in an outdoor environment. In the secondary study, gross α and gross β activities in soil and date palm pits samples were measured by a low background α/β counting system. Average values of gross α and gross β activities in soil and date palm pits samples were 5.761 ± 0.360 Bqkg^-1, 38.219 ± 8.619 Bqkg^-1 and 0.556 ± 0.142 Bqkg^-1, 24.266 ± 1.711 Bqkg^-1, respectively.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.263-264
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• 1996

We have solved the radiative transfer problem using a Sobolev approximation with an escape probability method in case of the supersonic expansion of a stellar envelope to an ambient medium. The radiation from the expanding envelope turns out to produce a P-Cygni type profile. In order to investigate the morphology of the theoretical P-Cygni type profile, we have treated $V{\infty},\;V_{sto},\;{\beta}$ (parameter for the velocity field), M and $\epsilon$ (parameter for collisional effect) as model parametrs. We have found that the velocity field and the mass loss rate affect the shapes of the P-Cygni type profiles most effectively. The secondarily important factors are $V{\infty},\;V_{sto}$. The collisional effect tends to make the total flux increase but not so .much in magnitude. We have infered some physical parameters of 68 Cyg, HD24912, and $\xi$ persei such as V$\infty$, M from the model calculation, which shows a good agreement with the observational results.

• Molecular & Cellular Toxicology
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• v.1 no.2
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• pp.124-129
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• 2005

Pro-inflammatory cytokines, such as tumor necrosis factor $(TNF)-{\alpha}$, interleukin-12 (IL-12) and interleukin $(IL-1)-{\beta}$, play a key role in causing inflammatory diseases, which are rheumatoid arthritis, Crohn's disease and sepsis. Accumulating evidences suggest that low level laser irradiation (LLLI) may have an anti-inflammatory action. However, there are few data regarding down regulation of Th1 immune response by using the diod typed laser emitting device for human patients. As a fundamental step in order to address this issue, we investigated immunological impact of the low level laser irradiation (10 mw laser diode with a wavelength of 630 nm) on expression of pro-inflammatory cytokines in murine immunocytes (splenocytes and peritoneal macrophages) in vitro. The LLLI on lipopolysaccharide (LPS 100 ng/ml)-stimulated murine splenocytes and macrophages, clearly down regulated mRNA expression of $TNF-{\alpha}$ and IL-12 in dose-dependent manner. In addition, LLLI significantly inhibits the NO production in the LPS-stimulated murine macrophages. This data suggests that LLLI (wavelength of 630 nm) may exert an anti-inflammatory action via modulation of pro-inflammatory cytokine and NO production pathway.

• Journal of the Korean Chemical Society
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• v.7 no.4
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• pp.257-263
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• 1963

The crystal structure of nicotinic acid hydrochloride has been determined by two-dimensional x-ray method. The unit cell is monoclinic with a = 7.21 ${\AA}$, b = 6.69 ${\AA}$, c = 7.54 ${\AA}$, ${\beta}=100^{\circ}$, space group $C{\frac{2}{2}}-P2_1$, and contains two formula units. Weissenberg diagrams have been taken along the a, b and c axes with Cu K${\alpha}$ radiation and the positions of the atoms have been fixed by means of two dimensional Patterson syntheses, a Fourier projection along the b-axis and trial and error method. The bond lengths are: pyridine ring C-C = 1.38, 1.39 ${\AA}$, C-N = 1.34, 1.36 ${\AA}$, carboxyl group $C_4-C_6$ = 1.46 ${\AA}$, $C_6-O_1$ = l.33 ${\AA}$, $C_6-O_2$ = 1.19 ${\AA}$. The ring nitrogen atom may be regarded as forming bifurcated hydrogen bond with an oxygen atom $O_2$ of one neighbouring molecule and with a neighbouring chlorine atom, being linked by forming a hydrogen bond with an other oxygen atom $O_1$ of above mentioned neighbouring molecule, in such a way that chains parallel to the c-axis are formed.

• Nuclear Engineering and Technology
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• v.3 no.1
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• pp.9-13
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• 1971

The levels of strontium-90 in milk produced in Korea were determined during the past six years. Milk samples were collected from dairies and market shops in seoul area. Strontium-90 in milk was separated from calcium using fuming nitric acid and purified radiochemically. After seculear equilibrium was completed, the radioactivity of yttrium-90 was counted in a low background beta counting system. The determination of stable calcium in milk was also made by volu-metric method using 0. 1 N potassium permanganate solution. The highest value of 34.9 pCi $^{90}$ Sr/g-Ca was determined in August, 1966 and the lowest value was 7.5 pCi $^{90}$ Sr/g-Ca in August, 1967. From the result we can say that levels of strontium-90 are decreasing year after year and are far bellow the maximum permissible level recommended by International Committe on Radiation Protection.

• Bulletin of the Korean Chemical Society
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• v.12 no.4
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• pp.371-373
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• 1991

The crystal structure of eprazinone dihydrochloride, $C_{24}H_{32}N_2O_2$${\cdot}$2HCl, has been determined from 2102 independent reflections collected on an automated Nonious CAD-4 diffractometer using graphite-monochromated $Mo-K\alpha$ radiation. The crystals are monoclinic, space group P$2_1$/n, with unit cell dimensions a=11.381(2), b=28.318(2), c=7.840(1) $\AA$, $\beta=92.45(2)^{\circ}$, ${\mu}=2.37$ c$m^{-1}$, F(000)=968, and Z=4. Final R value is 0.071 for independent 2102 observed reflections. The molecule assumes an extended conformation. The piperazine ring has a normal chair conformation and the four carbon atom are planar with a maximum displacement of 0.004 $\AA$ for C(18) atom. The two chloride ions are hydrogen bonded to the two piperazine nitrogen atoms [N(14)${\cdot}{\cdot}{\cdot}$Cl(1); 2.986(6) $\AA$ N(17)…Cl(2); 3.084(8) $\AA$].

• Bulletin of the Korean Chemical Society
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• v.11 no.5
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• pp.427-430
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• 1990

Cholesteryl aniline ($C_{33}H_{51}N$) is monoclinic, space group $P2_1$, with a = 9.020(3), b = 6.000(1), c = 27.130(9)${\AA},\;{\beta} = 98.22(2)^{\circ}$, Z = 2, Dc = 1.06 g/cm$^3$ and Dm = 1.04 g/cm$^3$. A diffraction data set was collected with Mo-$K_{\alpha}$ radiation (${\lambda} = 0.7107 {\AA}$) on a diffractometer with a graphite monochromator to a maximum 2${\theta}$ value of 50$^{\circ}$, by the ${\omega}-2{\theta}$ scan technique. The coordinates of the non-hydrogen atoms and their anisotropic temperature factors were refined by full-matrix least-squares methods to final R of 0.058. In cholesteryl group, bond distances were normal except in tail part, where high thermal vibration resulted in apparent shortening of the C-C distances. The crystal structure consists of bilayers of thickness $d_{001} = 27.13 {\AA}$, in each of which there is the tail to tail arrangement of molecules aligned in the unit cell with their long axes approximately parallel to the [104] axis. The two halves of the double layer are related to each other by the screw axis.

• Bulletin of the Korean Chemical Society
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• v.15 no.6
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• pp.432-436
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• 1994

Monomeric rhodium and iridium-diaryltetrazene complexes $Cp^*$M(RNN=NNR)($Cp^*$=1,2,3,4,5-pentamethylcyclope ntadienyl; M=Rh, Ir; R=Ph, 4-tolyl) have been synthesized from [$Cp^*MCl_2]_2$(M=Rh, Ir) and 2 equiv. of $[Li(THF)_x]_2(RN_4$R) in benzene. We have determined the crystal structure of (${\eta}^5$-pentamethylcyclopentadienyl)diphenyltetrazene iridium by using graphite-monochromated Mo-$K_a$ radiation. The compound was crystallized in the monoclinic space group $P2_{1/c}$ with a=13.781(3), b=9.035(l), c=17.699(3) ${\AA}$, and ${\beta}=111.93(l)^{\circ}$. An X-ray crystal structure of complex 1 showed a short N(2)-N(3) distance ($1.265 {\AA}$) consistent with the valence tautomer A with Ir(III) rather than Ir(I). All complexes are highly colored and decompose on irradiation at 254 nm. Electrochemical studies show that complex 1 displays a quasi-reversible reduction.