Our studies in the area of single electron transfer (SET) photochemistry have led to the discovery of efficient processes, in which regioselective formation of carbon-centered radicals takes place by nucleophile assisted desilylation of -trialkylsilyl substituted ether, thioether, amine and amide centered cation radicals. The rates of bimolecular desilylation of the intermediate cation radicals exceed those of other cation radical -fragmentation processes (e.g.,-deprotonation). This sereves as the basis for the design of highly regioselective, SET-induced photomacrocyclization reactions of polyether, polythioether, polyamide, and polypeptide linked phthalimides. Photocyclization reactions of trimethylsilyl-terminated substrates in these families are unique in that they produce polyfunctionalized macrocyclic substances in a highly efficient and regioselective manner. In addition, our studies in this area have led to important information about the factors that govern chemical and quantum efficiencies that should be applicable to a wide variety of redox processes promoted by SET from substrates containing more than one electron donor site.

Methanol oxidation effect on carbon supported Pt was investigated as a function of Pt content in a sample which is closely correlated with Pt particle sizes. After prolonged methanol oxidation the Pt particle size did not change within the experimental error ranges. The chemical shift and linewidth of CO adsorbed on Pt show non-linear behavior simply due to the Pt particle size difference. The Pt size variation difference between this work and the previous reports of the particle growths is explained by the experimental temperature difference.

A new salicylate-selective electrode based on the complex N,N'-1,4-butylene bis(3-methyl salicylidene iminato) copper(II) as the membrane carrier was developed. The electrode exhibits a good Nernstian slope of 59.1 1.0 mV/decade and a linear range of -1.0 M for salicylate. The limit of detection was M. It has a fast response time 10 s and can be used for more than three months. The selective coefficients were determined by the fixed interference method (FIM) and could be used in the pH range 4.5-10.5. It was employed as an indicator electrode for direct determination of salicylate in pharmaceutical samples.

We prepared 3-aryl-3-hydroxypyrrolidin-2-one and tricyclic 2-benzyl-9b-hydroxy-3,3a,5,9b-tetrahydro-2H-pyrrolo[3,4-c]quinoline-1,4-dione derivatives starting from the Baylis-Hillman adducts of isatin derivatives.

A macrocyclic ligand, N,N',N''-tribenzyl-2,11,20-triaza[3,3,3](2,6)pyridinophane (BAPP), was used to prepare an iron(II) complex as a nonheme model complex, (1). X-ray crystallography of a colorless crystal of 1 revealed that BAPP acted as a pentadentate ligand due to geometrical strain for the formation of a six-coordinate iron(II) complex by BAPP. As a result, the iron center revealed a significantly distorted square pyramidal geometry similar to that found in the active site of taurine dioxygenase (tauD). In the reaction of 1 with PhIO, no intermediate was observed in the UV-visible region of spectrometer at low temperatures. Catalytic oxidations of triphenyl phosphine with PhIO at revealed that 1 was able to convert triphenyl phosphine to triphenyl phosphine oxide.23; SSOCHKThioanisole was also oxidized to the corresponding methylphenyl sulfoxide under the same conditions.

Excitability is one of the basic and fundamental mechanisms utilized for signal transmission in living organisms. With reference to the condition by Marek and the condition by Schneider, we found a condition in which excitability with similar shapes can appear by chemical and electric perturbation. Our condition is constructed with 3 chemical channels and 1 electric channel, and can be used as a condition for a chemical spiking neuron and as a unit of a chemical spiking neural network.

LPC analogues including natural and unnatural LPC, 3-L-2-PC, acetylated LPC and ethylene glycol derivative are prepared from D-mannitol using in convenient procedures by only changing the synthetic sequences, and their protective activities against cecal ligation and puncture (CLP)-induced severe sepsis are compared. The chirality at C2 position in LPC is found to be required as (S)-configuration for sepsis inhibition, comparing from the protection activity between LPC 6 and unnatural LPC 8. The hydroxyl functionality is also very important and required at C2 or C3 position as shown in the protection activities of ethylene glycol analogue 11 and 3-L-2-PC 9.

Anomalously high ionic mobilities of H+ and are owing to the transfer of by the Grotthus chain mechanism. Molecular dynamics simulations for the system of 215 water including ion at 298.15 K using the OSS2 model [J. Chem. Phys. 109, 5547 (1998)] as a dissociable water model with the use of Ewald summation were carried out in order to study the dynamics of in water. The calculated ionic mobility of is in good agreement with the experimental result and the Grotthus chain mechanism is fully understood.

Aluminum nanotube has been fabricated by a physical vapor deposition/atmospheric pressure injection using an anodic porous alumina film as a template. The pore external-, and inside diameters and the length of the aluminum nanotubes fabricated by this method are 60 nm, 35 nm and 2 m, respectively. The structure of the fabricated aluminum nanotubes was examined by a kind of chemical treatment as extraction of copper on the cross-sectional area of these aluminum tubes in a mixed solution of and HCl by difference of ionization tendency between aluminum and copper. The composition of the aluminum nanotube was identified by the two dimensional Hybrid Plasma Equipment Model (HPEM) employing the inductively coupled plasma.ऐ돀ࡾ�⨀堘�⨀�⨀돐࢑�⨀��⨀႑�⨀뤏덐ₑ�⨀렏頏䢑�⨀਀䢑�⨀墑�⨀؀က墑�⨀?麆Ѐက肑�⨀肑�⨀

The synthesis of a new series of 1-methylcarbapenems having 5-(-disubstituted ethyl)pyrrolidine moiety is described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bacteria were tested and the effect of substituents on the pyrrolidine ring was investigated. A particular compound (VIh) having -hydroxy--piperazinylethyl substituted moiety showed the most potent activity.

Various off-the-shelf Lewis acids in conjunction with various onium salts are screened for coupling reaction of with epoxides. Among the tested ones, , or PPNCl), , and are proved to be highly active. Propylene oxide, epichlorohydrin, styrene oxide, and cyclohexene oxide can be converted over 90% yields to the corresponding cyclic carbonates without the use of organic solvents under mild conditions by 0.1-1.0 mol% catalyst charge.

Si-C composites were prepared by the carbonization of polyaniline (PAn) coated on silicone powder. The physical and electrochemical properties of the Si-C composites were characterized by particle-size analysis, X-ray diffraction, scanning electron microscopy, and battery electrochemical tests. The average particle size of Si was increased by the coating of Pan but somewhat reduced by the carbonization to give silicone-carbon composites. The co-existence of crystalline silicone and amorphous-like carbon was confirmed by XRD analyses. SEM photos showed that the silicone particles were well covered with carbonaceous materials, depending on the PAn content. Si-CLi cells were fabricated using the Si-C composites and tested using galvanostatic charge-discharge. Si-CLi cells gave better electrochemical properties than Si|Li cells. Si-CLi cells using Si-C from HCl-undoped precursor PAn showed better electrochemical properties than precursor PAn doped in HCl. The addition of an electrolyte containing 4-fluoroethylene carbonate (FEC) increased the initial discharge capacity. Also, another electrochemical test, the galvanostatic charge-discharge test with GISOC (gradual increasing of the state of charge) was carried out. Si-C(Si:PAn = 50:50 wt. ratio)|Li cell showed 414 mAh/g of reversible specific capacity, 75.7% of IIE (initial intercalation efficiency), 35.4 mAh/g of IICs (surface irreversible specific capacity).

By using two different computer simulation methods, of which one produces exact results while the other is based on the Wilemski-Fixman closure approximation, we evaluate the utility of closure approximation in calculating the rates of diffusion-controlled reactions involving a reactant with multiple reaction sites. We find that errors in the estimates of steady-state rate constants due to closure approximation are not so large. We thus propose an approximate analytic expression for the rate constant based on the closure approximation.䄠돀遠�⨀堘�⨀炟�⨀ᤠ돐邟�⨀ࢷ�⨀颟�⨀덐죙�⨀

In this paper a new theory is presented to treat the problem of stimulated absorption and emission of photons between energy levels from the standpoint of discrete quantum jumps. In order to implement the theory a scheme to avoid the quantum Zeno effect is proposed. Numerical simulations are performed to demonstrate that this approach does not contradict the principles of the standard wave mechanics. It is shown that with this approach one can obtain photon observation statistics as well.

In order to develop radiopharmaceuticals for targeting a serotonin receptor such as , histidine--arylpiperazines (AP) (C = alkyl, n = 2, 3, 4) were prepared in five steps with yields of 25%, 37% and 51%, respectively, and radiolabeled with the . The -Histidine-Cn-APs were prepared with a high yield (>99%) and characterized as a tridentate complex with a neutral charge to pass through the blood-brain barrier (BBB). The rhenium complexes with were also synthesised and comparative experiments were achieved to evaluate the nature of the complexes.

For the purpose of developing more effective chelating agents, we have synthesized a diethylene triamine pentaacetic acid(DTPA) analogue by using an amino acid. S-(N-Boc-aminophenyl)-Cys(t-Bu4-DTPA) methylester was prepared in 6 steps with total yield of 47.9%. For the sake of introducing a biomolecule to the DTPA derivative, a selective hydrolysis was performed with 3 M HCl/Ethylacetate = 1 : 3 (, 30 min, vigorous stirring). -Cys-DTPA and -Biotin-Cys-DTPA were prepared by mixing with DTPA derivatives at room temp in a HCl solution (pH = 5) and the radiochemical stabilities (> 99%) were maintained for over 6 hrs in vitro.�⨀਀က�⨀薊핾؀က㖋핾Āႎ�⨀਀ႎ�⨀邎�⨀Āက邎�⨀₎�⨀؀₎�⨀袎�⨀؀က袎�⨀ꂎ�⨀਀ꂎ�⨀肏�⨀̀က肏�⨀낎�⨀ऀ낎�⨀碏�⨀؀က碏�⨀邏�⨀਀邏�⨀႐�⨀̀က႐�⨀ꂏ�⨀Ԁꂏ�⨀࢐�⨀؀က࢐�⨀ₐ�⨀਀ₐ�⨀‘�⨀̀က‘�⨀ゐ�⨀⤀ゐ�⨀�⨀؀က�⨀႑�⨀਀႑�⨀邑�⨀̀က邑�⨀ₑ�⨀Ԁₑ�⨀袑�⨀؀က袑�⨀ꂑ�⨀਀ꂑ�⨀䂓�⨀Ԁက䂓�⨀낑�⨀Ḁ낑�⨀碒�⨀⼀碒�⨀ᄐ돀㡧�⨀堘�⨀悕�⨀돐肕�⨀��⨀袕�⨀섏덐颕�⨀쀏ꀏ
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A simple, sensitive and rapid spectrofluorimetric method was developed for determination of mefenamic acid in pharmaceutical preparation and human urine. The procedure is based on the oxidation of mefenamic acid with cerium (IV) to produce cerium (III), and its fluorescence was monitored at 354 nm after excitation at 255 nm. The variables affecting oxidation of drug were studied and optimized. Under the experimental conditions used, the calibration graphs were linear over the range 0.03-1.5 mg . The limit of detection was 0.009 mg and the relative standard deviation for 5 replicate determinations of mefenamic acid at 1.0 mg concentration level was 1.72%. Good recoveries in the range of 102-107 and 102-109% were obtained for pharmaceutical preparation and human urine, respectively. The proposed method was applied to the determination of MF in one pharmaceutical preparation and human urine. The amounts of mefenamic acid found are very similar to those obtained by a standard method.

During the synthesis of 4-fluorobenzaldehyde via the SNAr reaction of 4-nitrobenzaldehyde with TBAF, it was found that an equivalent amount of TBAF could oxidize benzaldehyde to benzoic acid. The reaction of 4-nitrobenzaldehyde with tetrabutylammonium fluoride (TBAF) gave 4-nitrobenzoic acid in high yield. Depending on the reaction conditions, other aromatic aldehydes produced acids with fewer amounts of alcohols. However, this type of oxidation has limited practical applications. Nevertheless, the mechanism is quite different from the Cannizzaro reaction because the amounts of the acid salt and alcohol formed were different.ꤠ돀遠�⨀堘�⨀킢�⨀脠돐�⨀ࢷ�⨀�⨀夠댐탣�⨀᠆?⨀㢣�⨀ㄠ덐䢣�⨀†

Four isostructural amino-acid-based polyoxomolybdates, {} (pro = proline, M = Co (1), Ni (2), Cu (3), Zn (4)), have been synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, IR spectrum, TG analysis. The structures of 1-4 are layered networks built up from {} units and {} octahedra, the uncoordinated water molecules occupying the interlayer regions.

The enantiomerically pure (2R,3S)- and (2R,3R)-3-amino-2-hydroxy-4-phenylbutanoic acids (AHPBA) 1 and 3 are readily obtained from D-glucono-a-lactone. Both AHPBAs are the structural key units of KMI derivatives which are the potent inhibitors of BACE 1 (-secretase) and HIV protease. Additionally, the obtained AHPBAs 1 and 3 are converted to dipeptides of bestatin stereoisomers 2 and 4