6A6B, 6A6C,and 6A6D-ditosylates of β-cyclodextrin

Regio-isomers, 6A6B, 6A6C, and 6A6D-ditosylates of β-cyclodextrin prepared by the reaction of β-cyclodextrin with tosyl chloride were easily and effectively separated through reversed phase column chromatography and assigned.     

Polycyclic N-hetero compounds. XXXVIII. Synthesis and evaluation of antidepressive activity of [1]benzothieno[2′,3′:4,5]furo[3,2-d]primidines and their precursors

Synthesis of [1]benzothieno[2′,3′:4,5]furo[3,2-d]pyrimidines is described. Antidepressive evaluation of these compounds and their precursors were screened by inhibitory action of reserpine-induced hypothermia.     

Two competing fragmentation processes in dimethoxybenzenes depending on their positional isomers: Elimination of CH3 and CHnO (n = 1–3) and formation of methoxycyclopentadienyl and protonated phenol ions

All the metastable transitions observed above m/z 39 in the first field-free region were compared for the three positional isomers of dimethoxybenzene. The observed isomer-dependent fragmentation processes, in particular the formation and decomposition of the m/z 95 (C₆H₇O)⁺ ion, are discussed in terms of two competing fragmentations [elimination of CH₃ and CH_nO (n = 1–3) and formation of methoxycyclopentadienyl and protonated phenol ions] and the relative energies of several isomers of the C₆H₇O⁺ ion calculated with molecular orbital theory.     

Enzyme-based discrimination between clockwise and counterclockwise isomers of unsymmetrically disubstituted β-cyclodextrins. 6A,6B- and 6A,6G-derivatives

6A,6X-Dideoxy-6A-phenylthio-6X-[(β-naphthylsulfonyl)oxyl]-β-cyclodextrins (X=G and B) (5 and 6) were prepared together with the other isomers (X=C, D, E, and F) (1–4), isolated by reversed-phase column chromatography, and structurally assigned by use of Taka amylolysis.     

1-Aminoisoindole as a useful π-system elongation unit

Nitration of 4,7-ethanoisoindoles gave 1-nitro derivatives in moderate yields. Reduction of a nitro to amino group was successfully performed by sodium hydrosulfite in the case of ethyl 3-nitro-4,7-ethanoisoindole-1-carboxylate. The amino derivative was converted to benzylidenaminoisoindoles based on the retro Diels-Alder reaction. Their UV-vis spectra showed strong absorptions at 500-700 nm.     

Flexibility of disagreement actions in negotiations

Negotiation games in which two players engage in disagreement games to determine their payoffs during the bargaining generally admit multiple perfect equilibrium outcomes, including inefficient ones. This paper shows that if the two players cannot change their disagreement actions as frequent as they bargain, then the set of perfect equilibrium payoffs shrinks. As disagreement actions become completely inflexible relative to the bargaining frequency, the set of equilibrium payoffs shrinks to Nash's (1953) bargaining solution with strategic threat. Received January 1999/Final version March 2001     

Synthesis and chemiluminescent activity of 8,9‐dihydrobenzo[g] pyridazino[4,5‐b]indole‐7,10(11H)‐diones

Substituted and unsubstituted naphthylamines were transformed into the corresponding triazole derivatives, which were converted to dimethyl 1H‐benz[g]indole‐2,3‐dicarboxylates by photocyclization. The reaction of the diesters with hydrazine hydrate gave the corresponding 8,9‐dihydrobenzo[g]‐pyridazino[4,5‐b]indole‐7,10(11H)‐diones (5) . One of compounds 5 was found to have chemiluminescent activity similar to luminol.     

Real-time multi-step predictors from data streams

An online multi-step prediction method is constructed based on data streams, for which using all observed data points for prediction is impractical. The proposed method is superior in prediction accuracy and computational time, at various prediction steps, compared to two simple extensions of Kwasniok and Smith [F. Kwasniok, L.A. Smith, Phys. Rev. Let. 92 (2004) 164101]. We apply our proposed prediction method to artificial data sets generated from the Lorenz-63 model and to measured wind speed data streams.     

Correlation study among oxygen permeability,molecular mobility,and amorphous structure change of poly(ethylene‐vinylalcohol copolymers) by moisture

Oxygen permeability and the free‐volume hole size (cavity size) of ethylene‐vinylalcohol copolymers (EVOH) indicate abnormal humidity dependence, that is, they have minimum values in the range of around 20–40% RH, not showing a monotonic increase with humidity. To clarify this abnormal phenomenon, we investigated its molecular mobility and amorphous structure change by means of solid‐state NMR and temperature‐modulated differential scanning calorimetry (TMDSC). The glass transition temperature (T_g) decreased with humidity. Specimens stored at 15–60% RH showed large enthalpy relaxation, and it was found that the amorphous structure became more compact and the molecular conformation became more stable by ageing within this range of humidity. Under these conditions, solid‐state NMR measurement showed a component with intermediate relaxation time in the amorphous region. The results obtained by TMDSC and solid‐state NMR showed a reduction in molecular mobility by densifying in the amorphous region under the condition of 15–60% RH. The fact that the oxygen permeability and the cavity size of EVOH indicate minimum values at low humidity are attributed to the reduction in molecular mobility by enthalpy relaxation. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1181–1191, 2009     

Current performance gains from utilizing the GPU or the ASIC MDGRAPE‐3 within an enhanced Poisson Boltzmann approach

Scientific applications do frequently suffer from limited compute performance. In this article, we investigate the suitability of specialized computer chips to overcome this limitation. An enhanced Poisson Boltzmann program is ported to the graphics processing unit and the application specific integrated circuit MDGRAPE‐3 and resulting execution times are compared to the conventional performance obtained on a modern central processing unit. Speed Up factors are measured and an analysis of numerical accuracy is provided. On both specialized architectures the improvement is increasing with problem size and reaches up to a Speed Up factor of 39 × for the largest problem studied. This type of alternative high performance computing can significantly improve the performance of demanding scientific applications. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009