• Journal of the Korean Chemical Society
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• v.32 no.4
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• pp.301-310
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• 1988

Reaction rates for mononuclear heterocyclic rearrangement of N-(5-phenyl-1,2,4-oxadiazol-3-yl)-N'-arylformamidines into 3-acylamino-1-aryl-1,2,4-triazoles were determined spectrophotometrically in dioxane/water (50 : 50, v/v). There are two different reaction paths according to pH. One is pH-independent path, the other is pH-dependent one. In pH-independent path, the result of substituent effect by IYT equation show that N-H bond breaking as well as new N-N bond formation controls the reaction rate. In pH-dependent path, concave-upward Hammett plot was observed. It can be concluded that new N-N bond formation is more advanced than N-H bond breaking in transition state for electron-donating substituents, but N-H bond breaking is more advanced than new N-N bond formation for electron-withdrawing substituents.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.173-181
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• 2011

Purpose : 2009 Pandemic influenza A (H1N1) virus was identified in March 2009 and subsequently caused worldwide outbreaks. We described the clinical and epidemiological characteristics of H1N1 influenza infection. Methods : We used retrospective medical chart reviews to collect data on the visiting patients from a single institute. H1N1 infection was confirmed in specimens with the use of a RT-PCR (real time reverse transcriptase polymerase chain reaction assay). Result : 6,836 patients had H1N1 RT-PCR test, and 2,781 were confirmed with H1N1 virus infection. 158 patients (5.7%) had hospital treatment and inpatients were significantly younger (5.4${\pm}$3.3 years) than outpatients (7.5${\pm}$3.9 years) among H1N1 virus confirmed patients. Oxygen, steroid, immunoglobulin, ventilator treatment was provided in a substantial proportion among pneumonia patients accompanying wheezy respiration. In addition more intensive care was needed in patients accompanying segmental, lobar, interstitial, mixed pneumonia and lung effusion (27.2%) than patients with bronchopneumonia (7.3%) among H1N1 virus infection confirmed patients. Seventy-one infants had oseltamivir treatment out of 83 infants under 1 year, and no significant side effects and complications were identified. Conclusion : In 2009 pandemic influenza A (H1N1), hospital treatment was needed in younger patients. Early intensive care was needed in pneumonia patients accompanying wheezy respiration, and patients accompanying segmental, lobar, interstitial, mixed pneumonia and lung effusion.

• Journal of the Korean Chemical Society
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• v.52 no.3
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• pp.249-256
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• 2008

3-Acetyl/Formyl 4-hydroxy-2H(1)-benzopyran-2-one on treatment with malonitrile and ethyl cyanoacetate yielded 1,1-dicyano-2-[4/-hydroxy-2/H(1)-benzopyran-2/-one-3/-yl] ethene/propene 2a-h and ethyl-2-cyano-3-[4/-hydroxy-2/H (1)-benzopyran-2/-one-3/-yl] propenoate/butenoate 3a-h respectively. The 1,3 dipolar reaction of 2a-h with NaN3 gave the tetrazole derivative 4a-h. 3a-h on cyclization with PPA gave 3-cyano-2H,5H-pyrano [3, 2-c] benzopyran-2,5-diones 5a-h which on 1,3 dipolar reaction with NaN3 to gave 3-(1/H-tetrazol-5/-yl)-2H,5H-pyrano[3, 2-c] benzopyran-2,5-diones 6a-h. The structures of the compounds have been established on the basis of the spectral and analytical data. All the compounds were screened for their antimicrobial activities and have been found to exhibited significant antibacterial activities. Compounds 2h and 4h showed the activity 50g/mL.

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.565-568
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• 1998

Novel mononuclear metal complexes with the formula $[M(Ph_2PC_6H_4NC_3H_6NC_6H_4PPh_2)]$ (M=Pd (1); M=Pt (2)) were obtained when N,N'-bis[2'-(diphenylphosphino)phenyl]propane-1,3-diamine, I was mixed with cisdichlorobis(diethylsulfide)palladium and platinum in the presence of NEt3. Two mononuclear metal compounds with the fomula [M(Ph2PC6H4NH)(SEt2)Cl] (M=Pd (3); M=Pt (4)) were synthesized from $M(SEt_2)2Cl_2$ and N-(2'-diphenylphosphinophenyl)-4-amino-1,1,1,5,5, 5-hexafluoro-3-penten-2-one, II by the elimination reaction of hexafluoro pentenone. The X-ray single crystal structures of 1 and 4 are described. X-ray single crystal diffraction analyses reveal that compound 1 is a mononuclear palladium compound with P,N,N,P-coordination mode and 4 is a mononuclear platinum compound with P,N-coordination mode.

• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.671-679
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• 2010

The geometrical parameters and binding energies of the benzene ion-water complex [$C_6H_6^+-(H_2O)_n$(n=1-5)] have been investigated using ab initio (MP2) and density functional theory (DFT) with large basis sets. The harmonic vibrational frequencies and IR intensities are also determined to confirm that all the optimized geometries are true minima. Also zero-point vibrational energies have been considered to predict the binding energies. The predicted binding energy of 8.6 kcal/mol for $C_6H_6^+-(H_2O)$ at the MP2/aug-cc-pVTZ level of theory is in excellent agreement with recent experimental result of $8.5{\pm}1$ kcal/mol.

• Journal of the Korean Chemical Society
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• v.28 no.5
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• pp.328-334
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• 1984

A series of phenyl N-benzenesulfonylchloroformimidate derivatives (p-H, p-Cl, p-CH3 & p-OCH3) were prepared and the hydrolysis of these compounds were studied kinetically at various pH by UV spectrophotometry in 1 ; 4 dioxane-water at $25^{\circ}C$. Hammett ${\rho}$ values measured at pH 5.0 (${\rho}$ = -0.45) and pH 10.0 (${\rho}$ = 0.40) indicate that the reaction proceeds via an azocarbonium ion intermediate in the acidic medium, whereas, it involves direct attack by hydroxide ion on the azomethine carbon atom occurs under the basic medium. The formation of stabilized azocarbonium ion species at pH 5.0 is also consistent with the large solvent effect(m = 1.3-1.5 & n = 5.0-5.5). On the basis of these findings, we may concluded that the hydrolysis of phenyl N-benzenesulfonylchloroformimidate derivatives proceeds by $SN_1$ below pH 8.0, however, above pH 10.0, the hydrolysis proceeds through $SN_2$ and in the range of pH 8.0-10.0, these two reactions occur competitively.

• Korean Journal of Crystallography
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• v.11 no.1
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• pp.46-51
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• 2000

The molecular structures of 2-SC₄H₃CH=NN(H)C/sub 6/H/sub 5/(C/sub 11/H/sub 10/N₂S) and (GaMe₂)₂(2-SC₄H₃CH=NNC/sub 6/H/sub 5/)₂(C/sub 26/H/sub 30/Ga₂N₄S₂) have been determined by X-ray diffraction. Crystallographic data for 2-SC₄H₃CH=NN(H)C/sub 6/H/sub 5/:orthorhombic space group P2₁2₁2₁, a=6.108(1)Å, b=7.593(1)Å, c=22.356(2)Å, V=1037.1(3)ų, Z=4, R=0.0613. Crystallographic data for (GaMe₂)₂(2-SC₄H₃CH=NNC/sub 6/H/sub 5/)₂:monoclinic space group P2₁/n, a=15.996(2) Å, c=9.879(3)Å, β=100.07.(2)°, V=2764.599)ų, Z=4, R=0.0503.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1690-1691
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• 2011

본 논문에서는 H1N1 인플루엔자 A 바이러스(influenza A H1N1 virus) 검출을 위한 산화아연 나노구조(zinc oxide nano structure) 기반의 전기화학적 면역센서를 제작하고 그 특성을 분석하였다. H1N1 인플루엔자 A 바이러스는 빠른 전파 속도 때문에 정확하고 빠른 검출이 필요하다. 먼저, 2 $mm^2$의 표면적을 갖는 패턴된 금 전극 위에 열수방식(hydrothermal method)으로 성장시킨 산화아연 나노구조가 선택적으로 형성되도록 리프트-오프(lift-off) 방법을 사용하였다. 0.01 M phosphate buffered saline(pH 7.4)에서 2 ${\mu}g$/mL 농도의 1차 항체를 정전기력에 의해 산화아연 나노구조에 고정화한 후, 10 pg/mL ~ 5ng/mL 농도의 H1N1 항원을 적용하여 포획 항체에 결합시키고 HRP(horseradish peroxidase) 효소가 결합된 검출 항체를 항원에 결합시키는 샌드위치 ELISA법을 이용하였다. HRP와 반응하는 TMB(3,3', 5,5'-tetramethylbenzidine)와 과산화수소가 포함된 acetate buffered 용액(pH 5)을 전해질로 사용하고 순환전압전류 측정법(cyclic voltammetry)으로 센서의 특성을 분석하였다. 측정된 순환전압전류그래프(cyclic voltammogram)에서 H1N1 항원 농도 10 pg/mL ~ 5 ng/mL의 응답 전류는 276.47 ${\pm}$ 21.72 nA (평균 ${\pm}$ 표준편차, n=4) ~ 478.89 ${\pm}$ 6.21 nA로 측정되었고, logarithmic하게 증가하는 응답 전류 특성을 보였다.

• Analytical Science and Technology
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• v.23 no.1
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• pp.68-73
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• 2010

In order to develop the square wave voltammetric method determining cimetidine in an ampoule for injection, $5.00{\times}10^{-4}\;M$ cimetidine HCl solutions prepared with phosphate buffers of various pH values (3.01~8.97) were investigated by SWV. The well defined single peak due to the electrochemical reduction of -C=N-C$\equiv$N- in the structure of cimetidine moved towards the cathodic direction by -0.051V/pH as the pH values were increased indicating the involvement of hydrogen in its reduction. The calibration curves of cimetidine HCl in the concentration range between $1.00{\times}10^{-5}\;M$ and $5.00{\times}10^{-3}\;M$ prepared using three phosphate buffers yielded the slopes of 127,407nA/M (pH 3.01), 115,125nA/M (pH 5.00) and 111,287nA/M(pH 7.00) with excellent linearities of $R^2{\geqq}0.9997$. When one ampoule of Tagma Inj.$^{(R)}$ was analyzed by standard addition method by SWV, the within-day precision study (n=4) on the day of sample preparation resulted in the contents of cimetidine as $203{\pm}3.8\;mg$ (102% of the specified contents, RSD of 1.9%) and the inter-day precision (n=4) through 5 days was reasonable as 1.3% of RSD.

• Membrane Journal
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• v.24 no.6
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• pp.423-430
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• 2014

PTMSP/LDH composite membranes were prepared by adding 0, 1, 3, and 5 wt% LDH contents to PTMSP. The gas permeability and selectivity for $H_2$, $N_2$, $CH_4$, $C_3H_8$, $n-C_4H_{10}$ were investigated as a function of LDH content. As LDH content of PTMSP/LDH composite membranes increased to 5 wt%, the gas permeability for $H_2$ and $N_2$ gradually decreased, while $n-C_4H_{10}$ permeability rapidly increased. The gas permeability for $CH_4$ and $C_3H_8$ was found to decrease for the membranes with LDH content range of 0~3 wt%, however increase in the range of 3~5 wt%. As LDH content of PTMSP/LDH composite membranes increased to 5 wt%, the selectivity of membranes gradually increased for $H_2$, $N_2$, $CH_4$, $C_3H_8$, $n-C_4H_{10}$ over $H_2$, $N_2$. However the selectivity for $C_3H_8$ and $n-C_4H_{10}$ over $CH_4$ increased in the range of LDH content 0~3 wt% but decreased in the range of 3~5 wt%. The $CH_4$ and $n-C_4H_{10}$ selectivity over $H_2$ and $N_2$ increased as $CH_4$ and $n-C_4H_{10}$ permeability increased. The $n-C_4H_{10}$ selectivity over $CH_4$ increased with increasing $n-C_4H_{10}$ permeability up to 182,000 barrer and decreased above 182,000 barrer of $n-C_4H_{10}$ permeability. The $C_3H_8$ selectivity over $H_2$ and $N_2$ was found to decrease as the $C_3H_8$ permeability increased from 46,000 to 50,000 barrer, but to increase with increasing permeability from 50,000 to 52,300 barrer and decrease again with increasing permeability from 52,300 to 60,000 barrer. The $C_3H_8$ selectivity over $CH_4$ was found to decrease with increasing $C_3H_8$ permeability up to 52,300 barrer but increase above 52,300 barrer.