• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.989-993
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• 2014

The molecular structures of 2,6-diaza-1,3,5,7-tetraoxaspiro[3,3]heptane (1) and its dinitro derivative, 2,6-dinitro-2,6-diaza-1,3,5,7-tetraoxaspiro[3,3]heptane (2), were fully optimized without symmetry constraints at $HF/6-31G^*$ level of theory. A bisected conformation with respect to the ring is preferred with a $C_2$ symmetric structure. The density of each molecule in the crystalline state was estimated to 1.12 and 2.36 $g/cm^3$ using PM3/VSTO-3G calculations from the molecular volume. The heat of formation was calculated for two compounds at the CBS-4M level of theory. The detonation parameters were computed using the EXPLO5 software: D = 6282 m/s, $P_{C-J}$ = 127 kbar for compound 1, D = 7871 m/s, $P_{C-J}$ = 307 kbar for compound 2, and D = 6975 m/s, $P_{C-J}$ = 170 kbar for 60% compound 2 with 40% TNT. Specific impulse of compound 1 in aluminized formulation when used as monopropellants was very similar to that of the conventional ammonium perchlorate in the same formulation of aluminum.

• Korean Journal of Crystallography
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• v.17 no.1
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• pp.6-9
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• 2006

Crystal structure of Bis(N-Methylphenazinium)-Tetracyanopalladate(II) hydrate has been determined by X-ray crystallography. Crystal data: $(C_{13}H_{11}N_2){_2}[Pd(cn)_4]{\cdot}H_2O$, Monocline, Space group $P2_1/b$(No=14), a=9.783(4), b=10.788(4), c=13.666(4) ${\AA},\;{\beta}=104.59(5),\;Z=2,\;V=1392.9{\AA}{^3},\;Dc=1.476gcm^{-3},\;F(000)=632,\;{\mu}=7.05cm^{-1}$. The structure was solved by Patterson method and refined by full matrix least-square methods using unit weights. The final R and S values were R=0.0257, Rw=0.0732, Rall=0.0283 and S=1.07 for 1930 observed reflections. Both cation and anion complexes are essentially planar and have dihedral angles of $10.16(4)^{\circ}$. The planar complex anions are sandwiched between slightly bent cations. The interplanar separations in one triad and between two triads are 3.419(3) and $3.402(4){\AA}$, respectively. The triads are stacked along b-axis.

• Macromolecular Research
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• v.11 no.4
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• pp.256-259
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• 2003

Measurements of Young's modulus, dielectric loss and a.c. conductivity have been carried out on EPDM rubber samples loaded with different concentrations of $CrCl_3$ (0,2,4 and 6 phr). The values of Young's modulus was found to be linearly dependent on the $CrCl_3$ content. Variation of the dielectric loss with temperature showed that $CrCl_3$ may act as plasticizer. However, at higher frequencies the dielectric loss was found to be independent of frequency and the rubber samples may behave as non-polar dielectric. Investigations of the a.c conductivity suggested that the conduction in these rubber samples can be described by small polaron tunneling. In addition, conductivity was found to increase with $CrCl_3$ content.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.110-118
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• 1983

A slimy non-spore-forming bacterium strain SAF-C isolated from bean stem and root was motile with flagella and identified to one of Agrobacterium radiobacter. Studies were made on the conditions necessary for maximal production of this acidic succinoglucan polysaccharide by this strain in shaken culture. Much production was observed with yeast extract,$(NH_4)_2\;HPO_4$, distillers' dried solubles(D.D.S.), as nitrogen source in the medium composed of 4% glucose, 0.5% nitrogen source, 0.3% $CaCO_3$. The yield was greatest with yeast extract and decreased in order with the above nitrogen source from 22.9% to 9.6 percent. A polysaccharide was produced in a yield of about 25% in a medium composed of 3% glucose, 0.4% D.D.S., 0.5% $K_2\;HPO_4$, 0.01% $MgSO_4{\cdot}7H_2O$.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.12 no.2
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• pp.222-247
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• 1999

The back ground and purpose : The acupuncture of oriental medicine is very important in treatments. Until now it has been researched according to the meridian and qi xue(氣血) phenomenon of oriental medicine's theory. As electroacupuncture is one of acupuncture treatments, it will show more objective index to observe the meridian and qi xue(氣血) phenomenon. And then, I studied the effects on the thermal change of the face following electroacupuncture treatment. Objective and Methods : This study was performed from January 1999 to March 1999 on 10 healthy students. The objective was divided into three groups, those were the control group A(n=10), the group B(n=10) of electroacupuncture on Hapkok($LI_4$), Samgan($LI_3$) and the group C(n=10) of electroacupuncture on Shinmun($H_7$), T' ongni($H_5$). First, in the control group A, we took a picture for 10 men without any stimulation with the Digital Infrared Thermograph Imaging(D.I.T.I.) and did 3min after, 10min after, 15min after, 25min after, 45min after respectively. Second, in the electroacupuncture treatment group B, we took a picture for 10 men without any stimulation, and then treat electroacupuncture on Hapkok($LI_4$), Samgan($LI_3$) and took a picture immediately(3min after), 10min after, 15min after and remove needle and took a picture in the same way respectively. Third, in the electroacupuncture treatment group C, we took a picture for 10 men without any stimulation, and then treat electroacupuncture on Shinmun($H_7$), T'ongni($H_5$) and took a picture in the second way respectively. Results: 1. In healthy men, average skin temperture about Yonghyang($LI_{20}$) area was higher than Soryo($G_{25}$) or Chich'ang($S_4$) area. They were Soryo($G_{25}$) area $31.495{\pm}0.766^{\circ}C$, Rt. Yonghyang($LI_{20}$) area $31.664{\pm}0.936^{\circ}C$, Lt. Yonghyang ($LI_{20}$)area $31.686{\pm}0.767^{\circ}C$, Rt. Chich'ang($S_4$) area $31.226{\pm}0.875^{\circ}$, Lt. Chich'ang ($S_4$) area $31.453{\pm}0.855^{\circ}C$. 2. In the control group A, the skin temperature of Soryo($G_{25}$) showed the increase or decrease in below ${\Delta}0.1^{\circ}C\;except\;0.265{\pm}0.594^{\circ}C$ in 25min, but not significantly. 3. About Soryo($G_{25}$) area, the skin temperature decreased significantly after electroacupuncture immediately. ${\Delta}T $of the group B was $-0.970{\pm}0.87\;1^{\circ}C$, which was larger than one of the group C which was $-0.707{\pm}0.624^{\circ}C$ at 3min. And then ${\Delta}T$ of the group C was increase valuable at 25min, 45min. 4. About Yonghyang($L1_{25}$) area, the left ${\Delta}T$ of the group B showed below $0.2^{\circ}C$ or so in contrast to the right it. In the group C, on the both side showed continous increase of temperature as following times. 5. About Chich'ang($S_4$) area, the skin temperature increased valuable $0.3^{\circ}C$ or so on the both side and later inclined to decrease in the group B but not significantly. In the group C, it increased valuable on the both side. 6. The skin temperature of electroacupuncture treatment group B, C were more increase than the control group A except Lt. Yonghyang($LI_{20}$) area in the group B. The temperature of group C were more increase than the group B wholly. Conclusion : The above results indicate that D.I.T.I. is a useful method to observe and fallow-up the effects and the changes by electroacupuncture stimulation on objective evaluation of phenomenon for the meridian system and character. Thus, continuous thermographic study will be needed for more clinical application such as acupuncture and medicine or laser therapy according to oriental medicine.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.1047-1051
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• 2012

The nucleophilic substitution reactions of (2R,4R,5S)-(+)-2-chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 2-sulfide with X-pyridines are investigated kinetically in acetonitrile at $5.0^{\circ}C$. The free energy relationships for substituent X variations in the nucleophiles exhibit biphasic concave upwards with a break point at X = 3-Ac. Unusual positive $\rho_X$ (= +4.73) and negative ${\beta}_X$ (= -0.75) values are obtained with the weakly basic pyridines, and rationalized by the isokinetic relationship with isokinetic temperature at $t_{ISOKINETIC}=39.3^{\circ}C$. A concerted mechanism involving a change of nucleophilic attacking direction from a frontside attack with the strongly basic pyridines to a backside attack with the weakly basic pyridines is proposed on the basis of greater magnitudes of selectivity parameters ($\rho_X$ = -6.15 and ${\beta}_X$ = 1.11) with the strongly basic pyridines compared to those ($\rho_X$ = 4.73 and ${\beta}_X$ = -0.75) with the weakly basic pyridines.

• Animal Systematics, Evolution and Diversity
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• v.12 no.4
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• pp.331-347
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• 1996

The geographic distribution and variation for Rhinogobius brunneus were surveyed by means of allozymic and morphological analyses and it was revealed that the Korean populations of R. brunneus comprise three distinct types, Type-A, Type-B, and Type-C, which show considerable differentiation to a degree of interspecific level(Rogers' S(1972): $S_{A-B}$=0.631, $S_{A-C}$=0.628, $S_{B-C}$=0.661). In addition, no evidence of gene flow among the types was found at sympatric area and it is assumed that reproductive isolation is completed. Moreover there is microhabitat segregation according to the distance from river mouth among each types and which segregation was regarded as a factor to facilitate reproductive isolating mechanism. Therefore, based on the evidence presented above, these three types of R. brunneus are considered as typical discrete species.

• Korean Journal of Crystallography
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• v.5 no.1
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• pp.1-6
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• 1994

Two possible space groups of the comfound, VP6N3018C24H:60, are: P 1, a=14.022(1), b=12.644(2), c= 12.640(1)A, a=8038(1), B=102.12(1), r=102.16(1), V=2124.1A3, Z=2, μ=0.47cm-1, d=1.46g/cm3, R=0.083 for 3350 independent reflections with Fo>4o IFI, and C2/c, a=19.32(2), b=16.32(2), c=14.02(1)A, B=105.98(5), β=105.98(5), V=4248.2A3, Z=4 R=0.083 for 1590 independent reflections with Fo>4c IFoI . In the space group P T, there are two monlecules in a unit cell. Vanadium atoms in the two monlecules occupy the two different special positions such that the complete monlecules are accomplished by the two independent center of symmetry. Therefore two different half molecules of bis(trimetaphosphate)vanadate and three molecules of tetraethylammonium are the asymmetric unit in a unit cell. In the space group C2/c, however, the vanadium atom is located at a special position with centrosymmetry, and a two-fold symmetry axis passes through C2/c, N2 and C25 atoms. Therefore the asymmrtic unit in a unit cell consists of a half molecule of bis(trimetaphosphate)vanadate and one and a half molecules of tetraethylammonium. All the molecular conformations in both space groups are very similar: six oxygen atoms coordinated to a vanadium atom in the bi s(trimetaphosphate)vanadate molecule form an octahedron and the four carbon atoms bonded to a nitrogen atom in the tetraethylammonium molecule are disordered so that the eight carbon atoms around nitrogen atom exhibit an irregular dodecahedral form.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.4
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• pp.373-382
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• 2000

Individual genetic susceptibilities to cancers may result from several factors including differences in xenobiotics metabolism to chemical carcinogens, DNA repair, altered oncogenes and suppressor genes, and environmental carcinogen exposures. Among them, genetic polymorphisms of metabolizing enzymes to chemical carcinogens have been recognized as a major important host factors in human cancers. They have two main types of enzymes: the phase I cytochrome P-450 mediating enzymes (CYPs) and phase II conjugating enzymes. The purpose of this study is to determine the frequencies of genotypes of phase I (CYP1A1 and CYP2E1) and phase II (NAT2) metabolizing enzymes in healthy control and head and neck cancer patients of Korean and to identify the relative high risk genotypes of these metabolizing enzymes to head and neck cancer in Korean. The author has analyzed 132 head and neck cancer patients and 113 healthy controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results were as following; 1. The frequencies of genotypes of CYP1A1, CYP2E1 and NAT2 in healthy control were as following; CYP1A1 exon 7 polymorphism; Ile/Ile: Ile/Val: Val/Val = 59.3%: 36.3%: 4.4% CYP2E1 Pst I polymorphism, C1/C1: C1/C2: C2/C2 = 61.1%: 32.1%: 6.2% NAT2 polymorphism; F/F: F/S: S/S = 43.4%: 48.7%: 8.0% 2. In analysis of phase I enzyme, Val/Val genotype in CYP1A1 exon 7 polymorphism and C2/C2 genotype in CYP2E1 Pst I polymorphism were associated with relative high risks to head and neck cancers (Odds' ratio: 2.09 and 1.37, respectively). 3. Among the genotypes of NAT2 enzyme polymorphism, S/S genotype of NAT2 enzyme had 1.03 times of relative risk to head and neck cancers. 4. In combined genotyping of CYP1A1, CYP2E1, and NAT2 enzymes polymorphisms, the patients with Val/Val and C1/C1, C2/C2 and fast acetylator, and Val/Val and fast acetylator had higher relative risks than the patients with each baseline of combined genotypes (Odds' ratio: 2.82, 1.98 and 2.1, respectively). These results suggest the combined genotypes of Val/Val and C1/C1, C2/C2 and fast acetylator, and Val/Val and fast acetylator were more susceptible to head and neck cancers in Korean. And genotyping of metabolizing enzymes could be useful for predicting individual susceptibility to head and neck cancer.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.4
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• pp.7-13
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• 2009

The paddy irrigation demand for Nakdong river basin in Korea due to the climate change have been analyzed using regional climate model outputs. High-resolution (27 ${\times}$ 27 km) climate data for SRES A2 scenario produced by the Meteorological Research Institute (METRI), South Korea, and the observed baseline climatology dataset (1971-2000) were used. The outputs from the ECHO-G GCM model were dynamically downscaled using the MM5 regional model by METRI. Maps showing the predicted spatial variations of changes in climate parameters and paddy irrigation requirements have been produced using the geographic information system. The results of this study showed that the average growing season temperature will increase steadily by 1.5 $^{\circ}C$ (2020s A2), 3.2 $^{\circ}C$ (2050s A2) and 5.2 $^{\circ}C$ (2080s A2) from the baseline (1971-2000) 19.8 $^{\circ}C$. The average growing season rainfall will change by -3.4 % (2020s A2), 0.0 % (2050s A2) and +16.5 % (2080s A2) from the baseline value 886 mm. Assuming paddy area and cropping pattern remain unchanged the average volumetric irrigation demands were predicted to increase by 5.3 % (2020s A2), 8.1 % (2050s A2) and 2.2 % (2080s A2) from the baseline value 1.159 ${\times}$ $10^6\; m^3$. These projections are different from the previous study by Chung (2009) which used a different GCM and downscaling method and projected decreasing irrigation demands. This indicates that one should be careful in interpreting the results of similar studies.