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41.
We describe a group of small-molecule inhibitors of Jun kinase (JNK)-dependent apoptosis. AEG3482, the parental compound, was identified in a screening effort designed to detect compounds that reduce apoptosis of neonatal sympathetic neurons after NGF withdrawal. We show that AEG3482 blocks apoptosis induced by the p75 neurotrophin receptor (p75NTR) or its cytosolic interactor, NRAGE, and demonstrate that AEG3482 blocks proapoptotic JNK activity. We show that AEG3482 induces production of heat shock protein 70 (HSP70), an endogenous inhibitor of JNK, and establish that HSP70 accumulation is required for the AEG3482-induced JNK blockade. We show that AEG3482 binds HSP90 and induces HSF1-dependent HSP70 mRNA expression and find that AEG3482 facilitates HSP70 production while retaining HSP90 chaperone activity. These studies establish that AEG3482 inhibits JNK activation and apoptosis by a mechanism involving induced expression of HSP proteins.  相似文献   
42.
We have made new measurements of partial molar enthalpies of solution, excess heat capacities, and excess volumes of mixtures of chloroform and dimethylsulfoxide. In combination with published vapor pressures and excess enthalpies the results of these measurements have been analyzed within the context of the ideal associated solution model to yield C p and V for the formation of AB and A2B complexes. It is shown that the ideal associated solution model is consistent with all of the available thermodynamic data for this system, indicating that nearly all of the deviations of this system from ideal solution behavior can be accounted for in terms of chemical interactions of the two components.  相似文献   
43.
Excess molar heat capacities C P E at constant pressure and excess molar volumes V E have been determined, as a function of mole fraction x1 at 25°C and atmospheric pressure, for 10 binary liquid mixtures containing either trichloromethane (series I) with C6H5CH3, or C6H5Cl, or C5H5N, or CH3COCH3, or C6H5NO2; 1,4-dioxane (series II) with (C2H5)3N, or (CH3)2CHOCH(CH3)2, or (CH3 2SO); or diisopropyl ether (di-1-methylethyl ether) (series III) with (C2H5)3N, or CHCl3. The dipole momentsp (10–30C-m) of the substances range from nearly 0 to 14.1 for nitrobenzene. The C P E of series I and III are all positive, with C P E (x1=0.5) (J-K–1-mol–1) ranging from 1.04 for {x1CHCl3+x2C6H5Cl} to 16.66 for {x1(CH3)2CHOCH(CH3)2+x2CHCl3}. In series II, the C P E are positive and small for {x11,4-C4H8O2+x2(CH3)2CHOCH(CH3)2}, S-shaped and small for {x11,4-C4H8O2+x2(C2H5)3N}, and negative and small for {x11,4-C4H8O2+x2(CH3)2SO}. The excess volumes are small and positive for {x1CHCl3+x2C6H5CH3}, S-shaped for {x1CHCl3+x2CH3COCH3}, {x11,4-C4H8O2+x2(C2H5)3N} and {x1(CH3)2CHOCH(CH3)2+x2(C2H5)3N}, and negative for the other systems.Presented at the Symposium, 76th CSC Congress, Sherbrooke, Quebec, May 30–June 3, 1993, honoring Professor Donald Patterson on the occasion of his 65th birthday  相似文献   
44.
1-Oxa-3S,4S,6R-triphenyl-2-cyclohexanone and its enantiomer were synthesized, and the structure was determined by NMR and X-ray crystallography. The X-ray crystal structure showed that the delta-lactone adopts a boat conformation in the solid. The X-ray data showed a shortened C-O bond between the carbonyl carbon and the ether oxygen, consistent with delocalization involving the ester group. (1)H and (13)C NMR measurements in acetone-d(6) showed that the lactone is biased in favor of a boat conformation. In the less polar solvent chloroform-d(1), changes in the (1)H NMR coupling constants indicate a shift in the equilibrium in favor of a less rigid twist-boat conformation. The IR absorption of the lactone carbonyl at 1740 cm(-)(1) would suggest a half-chair conformation inconsistent with the dominance of the boat forms shown by NMR and X-ray.  相似文献   
45.
Thirteen variously substituted α-ethylenic β'-allenic alcohols (1,5,6-triene-3-ols) have been synthesized by three different methods, for two of which the key step was the reaction of an organo copper reagent with a derivative of a β-hydroxy γ-ethylenic alcohol (1-ene-5-yne-3,7-diol). The[3,3]-sigmatropic rearrangement of these alcohols, following the heating of their solution in diglyme, leads to γ-dienic aldehydes and ketones. The yields are best (60–70%) for tertiary alcohols substituted on carbon 5. Comparisons of the reactivities of these 13 alcohols show that the mechanism of this rearrangement can probably vary, following the substitution from a cyclohexadiyl biradical process to a concerted pathway involving a cyclohexane transition state.  相似文献   
46.
Well-known Picker flow microcalorimeters for the differential measurements of volumetric heat capacities have been employed in conjunction with vibrating tube densimeters to determine the molar heat capacity, volume, and the apparent properties in dilute aqueous solutions for 17 organic solutes of moderate hydrophobicity. The dependence on concentration of the apparent properties allowed the limiting partial molar quantities at infinite dilution to be extrapolated and the limiting partial molar excess quantities to be evaluated. Comparison with available literature data shows good agreement. The application of group contribution rules to the limiting partial properties has been tested using the original method and parameters proposed by Cabani et al. The predicted values of the partial molar volumes are in fair agreement with the present data except for some less common solutes. With partial molar heat capacities, the agreement is less satisfactory. To improve the performance of the method, missing parameters for some types of monofunctional and bifunctional molecules have been evaluated.  相似文献   
47.
This paper presents a detailed experimental assessment of the effect of the thickness of flat energy directors (ED) on heat generation at the interface during ultrasonic welding. Power and displacement data showed clear differences caused by the change of thickness, related to heat concentration at the weld line during the process. The extent of the heat-affected zone was assessed by welding specimens without consolidation at different stages of the process. It was confirmed through optical microscopy that heat is generated at the interface and transferred to the bulk adherends earlier in the process for thinner ED. The analysis of their fracture surface under optimum welding conditions revealed signs of matrix degradation, leading to less consistent quality, likely due to faster heat generation rate in both the ED and the substrates, and incidentally, higher temperatures surrounding the energy director.  相似文献   
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