From 1975 to 2011, for thirty six years, the author and his collaborators have developed a variety of reducing and hydroborating agents, and applied them to organic synthesis, which involves the 1,2-reduction of ${\alpha}$,${\beta}$-unsaturated carbonyl compounds, stereoselective reduction of cycloalkanones, regioselective ring-opening of epoxides, partial reduction of carboxylic acid derivatives to aldehydes, regioselective addition to carbon-carbon multiple bonds, etc. by utilizing metal hydrides and the newly-devised the Meerwein-Ponndorf-Verley (MPV) type reagents. Such developments provide a new synthetic methodology making possible valuable selective reductions and hydroborations, not practical previously.

Details of the double-bond isomerization of 1-hexene over H-ZSM-5 were clarified using density functional theory. It is found that the reaction proceeds by a mechanism which involves the Br${\o}$nsted acid part of the zeolite solely. According to this mechanism, 1-hexene is first physically adsorbed on the acidic site, and then, the acidic proton transfers to one carbon atom of the double bond, while the other carbon atom of the double bond bonds with the Br${\o}$nsted host oxygen, yielding a stable alkoxy intermediate. Thereafter, the Br${\o}$nsted host oxygen abstracts a hydrogen atom from the $C_6H_{13}$ fragment and the C-O bond is broken, restoring the acidic site and yielding trans-2-hexene. The calculated activation barrier is 12.65 kcal/mol, which is in good agreement with the experimental value. These results well explain the energetic aspects during the course of double-bond isomerization and extend the understanding of the nature of the zeolite active sites.

Two lanthanide complexes, $[Ln(NO_3)_2(H_2O)_3(L)_2](NO_3)(H_2O)$ {Ln = Eu (1), Tb (2); L = 2-(4-pyridylium)-ethanesulfonate, $(4-pyH)^+-CH_2CH_2-SO_3^-)$}, were prepared from lanthanide nitrate and 4-pyridineethanesulfonic acid in $H_2O$ under microwave-heating conditions. Complexes 1 and 2 are isostructural, and the lanthanide metal in both complexes is coordinated to nine oxygen atoms. The pyridyl nitrogen in the ligand is protonated to give a zwitter ion that possesses an $NH^+$ (pyridyl) positive end and an $SO_3^-$ negative end. All O-H and N-H hydrogen atoms participate in hydrogen bonds to generate a two-dimensional (complex 1) or a three-dimensional network (complex 2). Complex 1 exhibits an intense red emission, whereas complex 2 exhibits an intense green emission in the solid state at room temperature.

This study investigates the sensitivity of a gas sensor to volatile organic compounds (VOCs) at various operating temperatures and catalysts. Nano-sized powdered $WO_3$ prepared by sol-gel and chemical precipitation methods was mixed with various metal oxides. Next, transition metals (Pt, Ru, Pd, and In) were doped on the surface of the mixture. Metal-$WO_3$ thick films were prepared using the screen-printing method. The physical and chemical properties of the films were studied by SEM/EDS, XRD, and BET techniques. The measured sensitivity to VOCs is defined as the ratio ($R_a/R_g$) of resistance ($R_{air}$) of $WO_3$ film in the air to resistance ($R_{gas}$) of $WO_3$ film in a VOCs test gas. The sensitivity and selectivity of the films were tested with various VOCs such as acetaldehyde, formaldehyde, methyl alcohol, and BTEX. The thick $WO_3$ film containing 1 wt % of Ru and 5 wt % of $SnO_2$ showed the best sensitivity and selectivity to acetaldehyde gas at an operating temperature of 300 $^{\circ}C$.

Under solvent-free conditions and in one-pot, a series of 2-amino-4-aryl-3-cyano-6-(3,4-dimethoxyphenyl)-pyridines and 4-aryl-3-cyano-6-(3,4-dimethoxyphenyl)-2(1H)-pyridinones were prepared using 3,4-dimethoxyacetophenone, an aldehyde, malononitrile (or ethyl cyanoacetate), and ammonium acetate in the presence of 3-methyl-1-(4-sulfonylbutyl)imidazolium hydrogen sulfate $[HO_3S(CH_2)_4MIM][HSO_4]$ (a Br${\o}$nsted acidic ionic liquid) as the catalyst in very short reaction time. The preference for the formation of more stable tautomers was consistence with the theoretical calculation using the Gaussian 03 program at the B3LYP hybrid density functional level.

The electronic structure and bonding in $Ti_2Pd$ and $Pd_2Ti$ alloys with and without hydrogen as an interstitial atom were studied by performing extended Huckel tight-binding band calculations. The hydrogen absorption near an octahedral site is found to be a favorable process in $Ti_2Pd$ rather than in $Pd_2Ti$. In metal hydrides, the metal-hydrogen bonding contribution is crucial to the stability of the system. The stronger interaction of hydrogen with Ti atoms in $Ti_2PdH_2$ than with Pd atoms in $Pd_2TiH_2$ is analyzed by perturbation theory.

A series of Ni(II) and Pd(II) complexes bearing N4-type tetradentate ligands, [Ni($X^1X^2$-6-$Me_2bpb$) 1] and [Pd($X^1X^2$-6-$Me_2bpb$) 2]; 6-$Me_2bpb$ = N,N'-(o-phenylene)bis(6-methylpyridine-2-carboxamidate), $X^1$ = Cl, H, or $CH_3$, $X^2$ = $NO_2$, Cl, F, H, $CH_3$, or $OCH_3$) were designed, synthesized, and characterized to investigate electronic and steric effects of ligand on the norbornene polymerization catalysts. Using modified methylaluminoxanes as an activator, the complexes exhibited high catalytic activities for the polymerization of norbornene and the nickel complexes exhibited better catalytic activity the palladium complexes. Ni complex 1a with $NO_2$ group on the benzene ring showed the highest catalytic activity of $4.9{\times}10^6$ g of PNBEs/$mol_{Ni}{\cdot}h$ and molecular weight of $15.28{\times}10^5$ g/mol with PDI < 2.30. Complexes with electron-withdrawing groups are more thermally stable (> 100 $^{\circ}C$), and tend to afford higher polymerization productivities than the ones having electron-donating groups. Amorphous polynorbornenes were obtained with good solubility in halogenated aromatic solvents. A vinyl addition mechanism has been proposed for the catalytic polymerization.

On the basis of potent HDAC-inhibitory activity and anticancer activity of SAHA, novel SAHA derivatives 3a-d and 7 with a bulky cap such as p-dimethylaminophenyl, 4-phenylaminophenyl, 4-phenyloxyphenyl, 9H-fluorenyl or naphthalenyl ring were synthesized starting from the corresponding aryl amines or naphthalenyl acetic acid using an EDC-mediated amide coupling reaction in the presence of HOBt followed by a nucleophilic addition-elimination reaction with hydroxylamine. Compounds 3b, 3c and 3d showed more potent inhibitory activity on total HDACs (14~27-fold), HDAC1 (8~15-fold), HDAC2 (1.3~25-fold) and HDAC7 (1~3-fold) and more potent anticancer activity (2~22-fold) against MCF-7, MDA-MB-231, MCF-7/Dox, MCF-7/Tam, SK-OV-3, LNCaP and PC3 human cancer cell lines than SAHA.

This report shows the rates of solvolyses for phenyl methanesulfonyl chloride ($C_6H_5CH_2SO_2Cl$, I) in ethanol, methanol, and aqueous binary mixtures incorporating ethanol, methanol, acetone, 2,2,2-trifluroethanol (TFE) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) are reported. Three representative solvents, studies were made at several temperatures and activation parameters were determined. The thirty kinds of solvents gave a reasonably precise extended Grunwald-Winstein plot, coefficient (R) of 0.954. The sensitivity values (l = 0.61 and m = 0.34, l/m = 1.8) of phenyl methanesulfonyl chloride (I) were smaller than those obtained for benzenesulfonyl chloride ($C_6H_5SO_2Cl$, II; l = 1.01 and m = 0.61) and 2-propanesulfonyl chloride ($(CH_3)_2CHSO_2Cl$, III; l = 1.28 and m = 0.64). As with the two previously studied solvolyses, an $S_N2$ pathway with somewhat ionization reaction is proposed for the solvolyses of I. The activation parameters, ${\Delta}H^{\neq}$ and ${\Delta}S^{\neq}$, were determined and they are also in line with values expected for a bimolecular reaction mechanism. The kinetic solvent isotope effect of 2.34 in $CH_3OH/CH_3OD$ is in accord with a bimolecular mechanism, probably assisted by general-base catalysis.

Sulfonated poly(fluorinated arylene ether)s (SDF-F)/poly[(N-vinylimidazole)-co-(3-methacryloxypropyl-trimethoxysilane)] (poly(VI-co-MPS))/poly(tetrafluoroethylene) (PTFE) is prepared for a high temperature proton exchange membrane fuel cell (PEMFC). The reaction of the membrane with phosphoric acid forms silicate phosphor, as a chemically bound proton carrier, in the membrane. Thus-formed silicate phosphor, nitrogen in the imidazole ring, and physically bound phosphoric acid act as proton carriers in the membrane. The physico-chemical and electrochemical properties of the membrane are investigated by various analytical tools. The phosphoric acid uptake and proton conductivity of the SDF-F/poly(VI-co-MPS)/PTFE membrane are higher than those of SDF-F/PVI/PTFE. The power densities of cells with SDF-F/poly(VI-co-MPS)/PTFE membranes at 0.6 V are 286, 302, and 320 mW $cm^{-2}$ at 150, 170, and 190 $^{\circ}C$, respectively. Overall, the SDFF/poly(VI-co-MPS)/PTFE membrane is one of the candidates for anhydrous HT-PEMFCs with enhanced mechanical strength and improved cell performance.

A kinetic study is reported for nucleophilic substitution reactions of 4-pyridyl X-substituted benzoates 7a-e with a series of alicyclic secondary amines in H2O. The Br${\o}$nsted-type plot for the reactions of 4-pyridyl benzoate 7c is linear with ${\beta}_{nuc}$ = 0.71. The corresponding reactions of 2-pyridyl benzoate 6, which is less reactive than 7c, resulted in also a linear Br${\o}$nsted-type plot with ${\beta}_{nuc}$ = 0.77. The fact that the more reactive 7c results in a smaller ${\beta}_{nuc}$ value appears to be in accord with the reactivity-selectivity principle. The aminolysis of 7c has been suggested to proceed through a stepwise mechanism in which breakdown of the intermediate is the rate-determining step (RDS). The Hammett plot for the reactions of 7a-e with piperidine consists of two intersecting straight lines, i.e., ${\rho}_X$ = 1.47 for substrates possessing an electron-donating group (EDG) and ${\rho}_X$ = 0.91 for those possessing an electron-withdrawing group (EWG). In contrast, the corresponding Yukawa-Tsuno plot exhibits excellent linear correlation with ${\rho}_X$ = 0.79 and r = 0.56. Thus, it has been concluded that the nonlinear Hammett plot is not due to a change in the RDS but is caused by stabilization of the ground state of the substrates possessing an EDG through resonance interaction between the EDG and the C=O bond of the substrates.

The $SnO_2$ with a particle size of about 300 nm instead of Ni is used in this study to overcome rapid catalytic deactivation by the formation of a $NiAl_2O_4$ spinal structure on the conventional Ni/${\gamma}$-$Al_2O_3$ catalyst and simultaneously impregnated the catalyst with potassium (K). The $SnO_2-K_2O$ impregnated Zeolite Y catalyst ($SnO_2-K_2O$/ZY) exhibited significantly higher ethanol reforming reactivity that that achieved with $SnO_2$ 100 and $SnO_2$ 30 wt %/ZY catalysts. The main products from ethanol steam reforming (ESR) over the $SnO_2$-$K_2O$/ZY catalyst were $H_2$, $CO_2$, and $CH_4$, with no evidence of any CO molecule formation. The $H_2$ production and ethanol conversion were maximized at 89% and 100%, respectively, over $SnO_2$ 30 wt %-$K_2O$ 3.0 wt %/ZY at 600 $^{\circ}C$ for 1 h at a $CH_3CH_2OH:H_2O$ ratio of 1:1 and a gas hourly space velocity (GHSV) of 12,700 $h^{-1}$. No catalytic deactivation occurred for up to 73 h. This result is attributable to the easier and weaker of reduction of Sn components and acidities over $SnO_2-K_2O$/ZY catalyst, respectively, than those of Ni/${\gamma}$-$Al_2O_3$ catalysts.

Nitrile-forming eliminations from $(E)-2,4,6-(NO_2)_3C_6H_2CH=NOC_6H_4-2-X-4-NO_2$ (1) promoted by $R_3NH/R_3NH^+$ in 70 mol % MeCN(aq) have been studied kinetically. When X = $NO_2$, the reactions exhibited second-order kinetics as well as Br$\"{o}$nsted ${\beta}$ = 0.63 and ${\mid}{\beta}_{lg}{\mid}$ = 0.34-0.46, and an E2 mechanism is evident. As the leaving group was made poorer (X = H, Cl, and $CF_3$), Br$\"{o}$nsted ${\beta}$ value increased from 0.63 to 0.85-0.89 without much change in the ${\mid}{\beta}_{lg}{\mid}$ value E2, indicating that structure of the transition state changed to an E1cb-like with extensive $C_{\beta}-H$ bond cleavage, significant negative charge development at the ${\beta}$-carbon, and limited $C_{\alpha}$-OAr bond cleavage.

Psychrophilic bacteria have acquired cold-resistance in order to protect themselves against freezing temperatures, which would otherwise be lethal. DnaK/DnaJ/GrpE systems are molecular chaperones which facilitate proper folding of newly synthesized proteins. Efficient folding processes are of great importance especially in a cold environment, such as the Arctic. In order to understand the protection mechanisms of psychrophilic bacteria against cold temperatures, we have explored a genome of KOPRI22215, tentatively identified as Psychromonas arctica, whose genome sequence has not yet been discovered. With an aim of searching for a coding gene of DnaK from KOPRI22215, we have applied a series of polymerase chain reactions (PCR) with homologous primers designed from other Psychromonas species and LA PCR in vitro cloning. 1917 bp complete coding sequence of dnaK from KOPRI22215 was identified including upstream promoter sites. Recombinant plasmids to overexpress PaDnaK along with EcDnaK (DnaK of E. coli) were then constructed in pAED4 vector and the pET-based system to induce PaDnaK expression by IPTG. Characterization assays of expressed PaDnaK were carried out by measuring survival rates upon 4 day incubation at 4 $^{\circ}C$: a refolding assay as molecular chaperone, and ATPase assay for functional activity. Taking account of all the data together, we conclude that PaDnaK was identified, successfully expressed, and found to be more efficient in providing cold-resistance for bacterial cells.

The synthesis of carbocyclic analogues of normal nucleosides has grown exclusively since they have shown potential antiviral and antitumor activities. Radiolabeled cis-1-[4-(hydroxy-methyl)-cyclopent-2-enyl]-5-$[^{124}I]$-iodocytosine (carbocyclic d4IC) and cis-1-[4-(hydroxy-methyl)-cyclopent-2-enyl]-5-(2-$[^{124}I]$iodovinyl)cytosine(carbocyclic d4IVC) were synthesized. The synthetic route employed Pd(0)-catalyzed coupling reaction together with organotin and exchange reaction for radioiodination as key reactions. Carbocyclic $[^{124}I]$d4IC gave more than 75% radiochemical yield with greater than 95% radiochemical purity. Carbocyclic $[^{124}I]$d4IVC gave more than 80% radiochemical yield with greater than 95% radiochemical purity.

Phosphonium montmorillonites (P-MMTs) were prepared by intercalating dodecyl tributyl phosphonium salt into sodium montmorillonite (Na-MMT) through an ion-exchange method. Microstructure and antibacterial activity of phosphonium montmorillonites were studied by FT-IR, TGA, XRD and Minimum Inhibitory Concentration (MIC), respectively. The results show that phosphonium montmorillonites exhibit higher thermal stability than conventional ammonium montmorillonites, the onset temperature of decomposition is higher than 300 $^{\circ}C$, and the basal spacing of phosphonium montmorillonites is enlarged compared to that of sodium montmorillonite. Phosphonium montmorillonites also show good antibacterial activity with the MIC against E. coli and S. aureus of 150 and 50 $mg{\cdot}L^{-1}$, respectively.

The nucleophilic substitution reactions of bis(Y-aryl) chlorophosphates (1) with substituted anilines and deuterated anilines are investigated kinetically in acetonitrile at 35.0 $^{\circ}C$. The kinetic results of 1 are compared with those of Y-aryl phenyl chlorophosphates (2). The substrate 1 has one more identical substituent Y compared to substrate 2. The cross-interaction between Y and Y, due to additional substituent Y, is significant enough to result in the change of the sign of cross-interaction constant (CIC) from negative ${\rho}_{XY}$ = -1.31 (2) to positive ${\rho}_{XY}$ = +1.91 (1), indicating the change of reaction mechanism from a concerted $S_N2$ (2) to a stepwise mechanism with a rate-limiting leaving group departure from the intermediate (1). The deuterium kinetic isotope effects (DKIEs) involving deuterated anilines ($XC_6H_4ND_2$) show secondary inverse, $k_H/k_D$ = 0.61-0.87. The DKIEs invariably increase as substituent X changes from electron-donating to electron-withdrawing, while invariably decrease as substituent Y changes from electron-donating to electron-withdrawing. A stepwise mechanism with a rate-limiting bond breaking involving a predominant backside attack is proposed on the basis of positive sign of ${\rho}_{XY}$ and secondary inverse DKIEs.

The pyridinolysis of methyl phenyl phosphinic chloride is investigated kinetically in acetonitrile at -20.0 $^{\circ}C$. The Hammett and Br${\o}$nsted plots for substituent X variations in the nucleophiles are biphasic concave downwards with a break point at X = H, and unusual positive ${\rho}_X$ (= 2.94) and negative ${\beta}_X$ (= -0.48) values are obtained for the strongly basic nucleophiles. A stepwise mechanism with a rate-limiting step change from bond breaking for the weakly basic pyridines to bond formation for the strongly basic pyridines is proposed on the basis of biphasic concave downward Hammett and Br${\o}$nsted plots. Unusual positive ${\rho}_X$ and negative ${\beta}_X$ values are rationalized by the isokinetic relationship. The pyridinolyses and anilinolyses of four $R_1R_2$P(=O)Cl-type substrates, dimethyl, diethyl, methyl phenyl, and diphenyl phosphinic chlorides in acetonitrile are compared to obtain systematic information on phosphoryl transfer reaction mechanism. The combination of the two ligands, Me and Ph, shows unexpected kinetic results for both the anilinolysis and pyridinolysis: greatest magnitude of $k_H/k_D$ (= 2.10) involving deuterated anilines $[XC_6H_4NH_2(D_2)]$ for the anilinolysis, and exceptionally fast rate and biphasic concave downward free energy correlation for the pyridinolysis.

A kinetic study is reported on nucleophilic substitution reactions of 4-nitrophenyl nicotinate 5 and isonicotinate 6 with alkali metal ethoxide EtOM (M = K, Na, and Li) in anhydrous ethanol at $25.0{\pm}0.1^{\circ}C$. Plots of pseudo-first-order rate constant $k_{obsd}$ vs. EtOM concentration exhibit upward curvature for the reactions of 5 and 6 with EtOK and EtONa but are almost linear for those with EtOLi. Dissection of $k_{obsd}$ into $k_{EtO^-}$ and $k_{EtOM}$ (i.e., the second-order rate constant for the reaction with dissociated $EtO^-$ and ion-paired EtOM, respectively) has shown that $k_{EtOK}$ ${\geq}$ $k_{EtONa}$ > $k_{EtO^-}$ but $k_{EtOLi}$ < $k_{EtO^-}$. It has been concluded that $K^+$ and $Na^+$ ions catalyze the reactions by increasing the electrophilicity of the carbonyl carbon atom through formation of a 4-membered cyclic transition state $TS_3$ or $TS_4$. However, $M^+$ ion catalysis has been found to be much less significant for the reactions of 5 and 6 than for the corresponding reactions of 4-nitrophenyl picolinate 4, which was reported to proceed through a 5-membered cyclic transition state $TS_2$. Although 5 and 6 are significantly more reactive than 4-nitrophenyl benzoate 3, the reactions of 5 and 6 result in smaller $k_{EtOK}/k_{EtO^-}$ ratios than those of 3. The electron-withdrawing ability of the nitrogen atom in the acyl moiety of 5 and 6 has been suggested to be responsible for the increase in reactivity and the decrease in the $k_{EtOK}/k_{EtO^-}$ ratio.

Various reaction conditions uding temperature, time and type and concentration of templates have been changed in order to facilely synthesize, especially with microwave (MW) heating, SAPO-34 molecular sieves. SAPO-34 molecular sieve can be synthesized rapidly with microwave irradiation from a gel containing tetraethylammonium hydroxide (TEAOH) as a template. However, other several templating molecules lead to SAPO-5 molecular sieve under microwave irradiation even though SAPO-34 is obtained by conventional electric synthesis from the same reactant gels. Moreover, SAPO-34 can be obtained more easily by increasing the TEAOH or silica concentration or by increasing the reaction temperature. SAPO-34 can be obtained within 5 min in a selected condition (high temperature of 210 $^{\circ}C$) with microwave heating, which may lead to a continuous production of the important material. SAPO-34 synthesized by microwave irradiation is homogeneous and small in size and shows acidity and a stable performance in the dehydration of methanol and 2-butanol to olefins, suggesting potential applications in acid catalysis.

1,2,4,5-tetraoxane, mono and dinitrate glycerol carbonate ester derivatives of stearic acid were synthesized along with the known 9(10)-keto methyl sterate, methoxy mono-nitrate and dinitrate of methyl stearate. Their cetane numbers (CNs) were investigated to evaluate their viability for use as CN improvers. The CN performances of tetraoxane and all of the nitrate derivatives were investigated at 500 and 1000 ppm concentrations and compared to that of a traditional CN improver 2-ethylhexyl nitrate (2-EHN). The experimental results suggest that all derivatives evaluated in this study showed better CN improvement than base diesel fuel. Specifically, the 1,2,4,5-tetraoxane derivative of stearic methyl ester was superior to all derivatives studied, also being superior to 2-EHN. We also discussed the correlations between the observed CN trends and thermo-analytical data resulted from thermo gravimetric analysis curves (TGA) and differential scanning calorimetry (DSC).

The effects of convection on the measurement of the diffusion coefficients of liquids by the pulsed gradient spin echo (PGSE) NMR method at low temperature are discussed. To examine the generation of convective flows, we used four different types of sample tubes in the diffusion measurements with temperature variation; a normal 5 mm NMR tube, a Shigemi tube, an ELISE type tube, and a capillary tube. Below room temperature, the calculated diffusion coefficients of chloroform in 5 mm o.d. type tubes increased with decreasing temperature, while those in the capillary tube decreased linearly. The convective flow was found to be significant even at low temperature and it seemed to be mainly induced by the transverse temperature gradient. It was also found that the capillary tube was most appropriate to measure the diffusion coefficients, since its small diameter is effective in suppressing the convective flows at both high and low temperatures.

The modification of a gas diffusion layer (GDL), a vital component in polymer electrolyte fuel cells, is described here for use in the electrochemical detection of antibody-antigen biosensors. Compared to other substrates (gold foil and graphite), mouse anti-rHBsAg monoclonal antibody immobilized on gold-coated GDL (G-GDL) detected analytes of goat anti-mouse IgG antibody-ALP using a relatively low potential (-0.0021 V vs. Ag/AgCl 3 M NaCl), indicating that undesired by-reactions during electrochemical sensing should be avoided with G-GDL. The dependency of the signal against the concentration of analytes was observed, demonstrating the possibility of quantitative electrochemical biosensors based on G-GDL substrates. When a sandwich method was employed, target antigens of rHBsAg with a concentration as low as 500 ng/mL were clearly measured. The detection limit of rHBsAg was significantly improved to 10 ng/mL when higher concentrations of the 4-aminophenylphosphate monosodium salt (APP) acting on substrates were used for generating a redox-active product. Additionally, it was shown that a BSA blocking layer was essential in improving the detection limit in the G-GDL biosensor.

A temperature- and coverage-dependant quasi-reversible change in two-photon photoemission (2PPE) of chemisorbed 1-phenyl-1-propyne (PP) on Cu(111) is reported. For PP on Cu(111) at 300 K probed at a photon energy of 4.13 eV, two broad peaks of comparable intensity show final state energies of 7.25 and 7.75 eV above the Fermi level. The former peak could be assigned to the first image potential state (IS, n = 1) and/or unoccupied molecular orbital (UMO), located at 3.1 eV above the Fermi level. The latter is plausibly attributed to a mix of unoccupied higher-order IS (and/or UMO) and occupied surface state (SS) of Cu(111). With decreasing the temperature, the former 2PPE peak shows a shift in position by about 0.2 eV, and the latter exhibits a dramatic increase in intensity. In the system, intermolecular interactions (and/or order-disorder transition) of PP and substrate lattice temperature may play a significant role in change in photoexcitation lifetime (or excitation cross-section), and the unoccupied molecular orbital (UMO)-metal (IS) charge transfer coupling. Our unique 2PPE results provide a deeper insight for understanding photoexcitation charge transfer with temperature in an organic molecule/metal system.

The stable conformers of glycine and the inter-conversions between them were studied theoretically at various levels of theory, B3LYP, MP2, CCSD and CCSD(T), in the gas phase and in aqueous solution. In aqueous solution, the structures examined by use of the conductor-like polarizable continuum model (CPCM) with various cavity models, UA0, UAHF, UAKS, UFF, BONDI and PAULING, and by use of a discrete/continuum solvation model with eight water clusters. The Gibbs free energy differences between the neutral (NE) and zwitterionic conformers (ZW), ${\Delta}G_{Z-N}[=G_{ZW}-G_{NE}]$, in aqueous solution were well reproduced by using the BONDI and PAULING cavity models. However the ${\Delta}G_{Z-N}$ values were underestimated in other cavity models, although the ZW conformers existed as stable species in aqueous solution. In the studies of a discrete/continuum solvation model with eight water clusters, gas phase results are still insufficient to reproduce the experimental findings. However the ${\Delta}G_{Z-N}$ values calculated by use of CPCM method in aqueous solution agreed well with the experimental ones.

The vibronically well-resolved emission spectrum was recorded from the corona discharge of precursor 2,3,4-trifluorotoluene in a corona excited supersonic expansion with a pinhole-type glass nozzle using a long-path monochromator in the visible region. From the analysis of the observed spectrum, we found the evidence of the presence of the difluorobenzyl radicals in the corona discharge of the precursor. A possible mechanism is proposed for the formation of difluorobenzyl radicals in the gas phase on the basis of the observed emission intensity of the difluorobenzyl radicals produced.

The nucleophilic substitution reactions of dicyclohexyl phosphinic chloride [3; $cHex_2$P(=O)Cl] with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at 60.0 $^{\circ}C$. The anilinolysis rate is too slow to be rationalized by the stereoelectronic effects. The rate is contrary to expectations for the electronic influence of the two ligands and exhibits exceptionally great negative deviation from the Taft's eq. The deuterium kinetic isotope effects (DKIEs) involving deuterated anilines invariably change from primary normal ($k_H/k_D$ > 1; max $k_H/k_D$ = 1.10 with X = 4-MeO) with the strongly basic anilines (X = 4-MeO, 4-Me, 3-Me) to secondary inverse ($k_H/k_D$ < 1; min $k_H/k_D$ = 0.673 with X = 3-Cl) with the weakly basic anilines (X = H, 4-F, 4-Cl, 3-Cl). A concerted $S_N2$ mechanism is proposed on the basis of both secondary inverse and primary normal DKIEs. The obtained DKIEs imply that the fraction of a frontside attack increases as the aniline becomes more basic. A hydrogen-bonded, four-center-type transition state is suggested for a frontside attack, while the trigonal bipyramidal pentacoordinate transition state is suggested for a backside attack.

We report a highly sensitive surface-enhanced Raman scattering (SERS) platform for the selective trace analysis of mercury (II) ions in drinkable water using aptamer-conjugated silver nanoparticles. Here, an aptamer designed to specifically bind to $Hg^{2+}$ ions in aqueous solution was labelled with a TAMRA moiety at the 5' end and used as a Raman reporter. Polyamine spermine tetrahydrochloride (spermine) was used to promote surface adsorption of the aptamer probes onto the silver nanoparticles. When $Hg^{2+}$ ions are added to the system, binding of $Hg^{2+}$ with T-T pairs results in a conformational rearrangement of the aptamer to form a hairpin structure. As a result of the reduced of electrostatic repulsion between silver nanoparticles, aggregation of silver nanoparticles occurs, and the SERS signal is significantly increased upon the addition of $Hg^{2+}$ ions. Under optimized assay conditions, the concentration limit of detection was estimated to be 5 nM, and this satisfies a limit of detection below the EPA defined limit of 10 nM in drinkable water.

Serotonin or 5-hydroxytryptamine subtype 2C ($5-HT_{2C}$) receptor belongs to class A amine subfamily of G-protein-coupled receptor (GPCR) super family and its ligands has therapeutic promise as anti-depressant and -obesity agents. So far, bovine rhodopsin from class A opsin subfamily was the mostly used X-ray crystal template to model this receptor. Here, we explained homology model using beta 2 adrenergic receptor (${\beta}$2AR), the model was energetically minimized and validated by flexible ligand docking with known agonists and antagonists. In the active site Asp134, Ser138 of transmembrane 3 (TM3), Arg195 of extracellular loop 2 (ECL2) and Tyr358 of TM7 were found as important residues to interact with agonists. In addition to these, V208 of ECL2 and N351 of TM7 was found to interact with antagonists. Several conserved residues including Trp324, Phe327 and Phe328 were also found to contribute hydrophobic interaction. The predicted ligand binding mode is in good agreement with published mutagenesis and homology model data. This new template derived homology model can be useful for further virtual screening based lead identification.

A series of isoxazol-indolin-2-one was designed for GSK-3${\beta}$ inhibitors as novel anticancer agents based on their binding mode analysis in GSK-3${\beta}$ crystal structure. Total 21 compounds were synthesized and evaluated for their inhibitory activity against two tumor cell lines (DU145 and HT29). Most of the synthesized compounds were potent with above 80% inhibitory activity at 100 ${\mu}M$, and several compounds were examined for inhibitory activity against GSK-3${\beta}$. Among them, 15(Z) ($R_1$=H, $R_2$=3-Cl-phenyl) was most active with 78% inhibition of tumor cell line (HT29) at 20 ${\mu}M$ and 72% inhibition of GSK-3${\beta}$ at 20 ${\mu}M$.

AgNPs (silver nanoparticles) has been widely used for the commercial products, which have antimicrobial agent, medical devices, food industry and cosmetics. Despite, AgNPs have been reported as toxic to the mammalian cell, lung, liver, brain and other organs and many researchers have investigated the toxicity of AgNPs. In this study, we investigated toxicity of the AgNPs to the liver cell using metabolomics based on HRMAS NMR (High Resolution Magic Angle Spinning Nuclear Magnetic Resonance) technics, which could apply to the intact tissues or cells, to avoid the sample destruction. Target profiling and multivariative statistical analysis were performed to analyze the 1D $^1H$ spectrum. The results show that the concentrations of many metabolites were affected by the AgNPs in the liver cell. The concentrations of glutathione (GSH), lactate, taurine, and glycine were decreased and most of amino acids, choline analogues, and pyruvate were increased by the AgNPs. Moreover, the levels of the metabolites were recovered upto similar level of metabolites in the normal cell by the pre-treatment of NAC, external antioxidant. The results suggest that the depletion of the GSH by the AgNPs might induce the conversion of lactate and taurine to the pyruvate.

Molecular dynamics simulation is used to study the binary collisions of nanometer-sized droplets of argon in the presence of a surrounding gas. By systematically varying the droplet size, the impact parameter and the velocity of collision, the outcome of such collisions were examined and they can be classified into coalescence, separation and shattering. If one of the colliding droplets is half or less than the other in diameter, a shattering is not possible to occur. The threshold of impact parameter for a given separation was studied by adjusting the Weber number. Overall nanoscale droplets were more likely to coalesce than the macroscopic sized ones due to their high surface-to-volume ratio.

Matrix metalloproteinases (MMPs), a family of zinc-containing endopeptidases, participate in many normal processes such as embryonic development and wound repair, and in many pathological situations such as cancer, atherosclerosis, and arthritis. Peptidomimetic MMP inhibitors were designed and synthesized with N-formylhydroxylamine (retrohydroxamate) as a zinc-binding group and various side chains on the ${\alpha}$, P1', and P2' positions. Using in vitro MMP assays with purified MMPs (MMP-1, MMP-2, MMP-3, MMP-9, and MMP-14) and fluorogenic peptide substrates, it was found that compounds 2d and 2g selectively inhibit gelatinases (MMP-2 and MMP-9) and interstitial collagenase (MMP-1). They also inhibited the chemo-invasion of fibrosarcoma HT-1080 cells and tube formation of human umbilical vascular endothelial cells in a dose-dependent manner. Our results suggest that retrohydroxamate-based MMP inhibitors, especially compounds 2d and 2g, have the potential to be used as therapeutic drugs for cancer and other MMP-related diseases.

A semi-continuous and automated method for quantifying atmospheric ammonia at the parts per billion level has been developed. The instrument consists of a high efficiency diffusion scrubber, an electrolytic on-line anion exchange device, and a conductivity detector. Water soluble gases in sampled air diffuse through the porous membrane and are absorbed in an absorbing solution. Interferences are eliminated by using an anion exchange devises. The electrical conductivity of the solution is measured without chromatographic separation. The collection efficiency was over 99%. Over the 0-200 ppbv concentration range, the calibration was linear with $r^2$ = 0.99. The lower limit of detection was 0.09 ppbv. A parallel analysis of Seoul air over several days using this method and a diffusion scrubber coupled to an ion chromatography system showed acceptable agreement, $r^2$ = 0.940 (n = 686). This method can be applied for ambient air monitoring of ammonia.

Using first principles density functional theory the formation energies of various binary compounds of lithium graphite and its homologues were calculated. Lithium and graphite react to form $Li_1C_6$ (+141 mV) but not form $LiC_4$ (-143 mV), $LiC_3$ (-247 mV) and $LiC_2$ (-529 mV) because they are less stable than lithium metal itself. Properties of structure and reaction potentials of $C_5B$, $C_5N$ and $B_3N_3$ materials as iso-structural graphite were studied. Boron and nitrogen substituted graphite and boron-nitrogen material as a iso-electronic structured graphitic material have longer graphene layer spacing than that of graphite. The layer spacing of $Li_xC_6$, $Li_xC_5B$, $Li_xC_5N$ materials increased until to x=1, and then decreased until to x=2 and 3. Nevertheless $Li_xB_3N_3$ has opposite tendency of layer spacing variation. Among various lithium compositions of $Li_xC_5B$, $Li_xC_5N$ and $Li_xB_3N_3$, reaction potentials of $Li_xC_5B$ (x=1-3) and $Li_xC_5$ (x=1) from total energy analyses have positive values against lithium deposition.

Several studies have demonstrated that nanoparticles (NPs) have toxic effects on cultured cell lines, yet there are no clear data describing the overall molecular changes induced by NPs currently in use for human applications. In this study, the in vitro cytotoxicity of three oxide NPs of around 100 nm size, namely, mesoporous silica (MCM-41), iron oxide ($Fe_2O_3$-NPs), and zinc oxide (ZnO-NPs), was evaluated in the human embryonic kidney cell line HEK293. Cell viability assays demonstrated that 100 ${\mu}g/mL$ MCM-41, 100 ${\mu}g/mL$ $Fe_2O_3$, and 12.5 ${\mu}g/mL$ ZnO exhibited 20% reductions in HEK293 cell viability in 24 hrs. DNA microarray analysis was performed on cells treated with these oxide NPs and further validated by real time PCR to understand cytotoxic changes occurring at the molecular level. Microarray analysis of NP-treated cells identified a number of up- and down-regulated genes that were found to be associated with inflammation, stress, and the cell death and defense response. At both the cellular and molecular levels, the toxicity was observed in the following order: ZnO-NPs > $Fe_2O_3$-NPs > MCM-41. In conclusion, our study provides important information regarding the toxicity of these three commonly used oxide NPs, which should be useful in future biomedical applications of these nanoparticles.

The effect of the addition of ionic liquids with four different cations (imidazolium, pyrrolidinium, piperidinium and pyridinium) on the performance of dye-sensitized $TiO_2$ solar cells based on electrolytes containing a t-butylpyridine (TBP) in 3-methoxypropionitrile (MPN) was studied. A total of 18 ionic liquids with mono-, di- and tri-alkyl derivatives were used in the present study, and among them a pyridinium cation with a mono-alkyl group showed better cell efficiency than the others. The best photoelectric conversion efficiency, 7.213%, was obtained using 1-hexylpyridinium iodide with an open-circuit photovoltage ($V_{oc}$) = 0.731 V, a short-circuit photocurrent density ($J_{sc}$) = 16.175 $mA/cm^2$, and a fill factor (ff) = 0.610 under AM1.5 and 100 $mW/cm^2$ illumination.

We studied the interaction of 3,3',3'',3'''-ethylenetetrakis-4-hydroxycoumarin (EHC) with bovine serum albumin (BSA) in acetate buffer and phosphate buffer with different pH values by UV-vis absorption spectrometry and fluorescence spectrometry respectively. It was found that the pH values of the buffer solutions had an effect on the interaction process. In acetate buffer of pH 4.70, the carbonyl groups in EHC bound to the amino groups in BSA by means of hydrogen bond and van der Waals force, which made the extent of peptide chain in BSA changed. By contrast, in phosphate buffer of pH 7.40, hydrophobic force played a major role in the interaction between EHC and BSA, while the hydrogen bond and van der Waals force were also involved in the interaction. The results of spectrometry indicated that BSA could enhance the fluorescence intensity of EHC by forming a 1:1 EHC-BSA fluorescent complex through static mechanism at pH 4.70 and 7.40 respectively. Furthermore, EHC bound on site 1 in BSA.