Self-assembled coordination cage 1 was found to accelerate Diels–Alder reactions in an aqueous media: e.g., 113-fold acceleration was observed in the reaction of isoprene with naphthoquinone.

The optical diffusion coefficient in a homogeneous turbid medium with high absorption was determined by steady-state measurements of the light transmission under the infinite-boundary condition. The intensity of the transmission was well described by the solution of the optical diffusion equation. Moreover, the optical diffusion coefficient D was given by a constant, (3 mu'(s))-1, where mu'(s) is the reduced scattering coefficient, up to the absorption coefficient of about 0.3 mu'(s). These results mean that attenuation by absorption only contributes to exponential attenuation along the optical path defined by the scattering coefficient and geometry of the system even in high-absorption turbid media such as the pathological living tissues of bleeding or haematoma.

1 Effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, pravastatin and simvastatin, on the myocardial level of coenzyme Qi0, and on mitochrondrial respiration were examined in dogs.2 Either vehicle (control), pravastatin (4 mg kg-'day-), or simvastatin (2 mg kg-'day-') was administered orally for 3 weeks. First, the myocardial tissue level of coenzyme Qio was determined in the 3 groups. Second, ischaemia was induced by ligating the left anterior descending coronary artery (LAD) in anaesthetized open chest dogs, pretreated with the inhibitors. After 30 min of ischaemia, nonischaemic and ischaemic myocardium were removed from the left circumflex and LAD regions, respectively, and immediately used for isolation of mitochondria. The mitochondrial respiration was determined by polarography, with glutamate and succinate used as substrates. 3 Simvastatin significantly decreased the myocardial level of coenzyme Qio, but pravastatin did not. 4 Ischaemia decreased the mitochondrial respiratory control index (RCI) in both groups. Significant differences in RCI between nonischaemic and ischaemic myocardium were observed in the control and simvastatin-treated groups. 5Only in the simvastatin-treated group did ischaemia significantly decrease the ADP/O ratio, determined with succinate. 6 The present results indicate that simvastatin but not pravastatin may cause worsening of the myocardial mitochondrial respiration during ischaemia, probably because of reduction of the myocardial coenzyme Qio level.

Tetrahedral organosilanols E[C6H4Si(i-Pr)2OH]4 (E = C, 2a; E = Si, 2b) as well as octahedral organosilanols Si8O12(CHCHC6H4SiR2OH)8 (R = i-Pr, 5a; R = Ph, 5b) have been derived from tetraphenylmethane and -silane (1a,b) and octavinyloctasilsesquioxane (3) designed for self-assembly of 3D hydrogen-bonding networks possessing large porosity. X-ray analyses following crystallization of 2a,b from THF/benzene and either hexane or heptane revealed adamantane-type networks with hydrogen bonds between the silanols of four separate molecules and selective inclusion of hexane or heptane, respectively. Upon changing the mixed solvent to THF/benzene/cyclohexane, X-ray analysis of 2a showed an inclusion compound of composition 2a·1.5benzene. TOPOS analyses of 2a·1.5benzene demonstrated a non-adamantane-type framework with sra network topology. Crystallization of 5a,b from acetone/benzene followed by X-ray analyses confirmed the production of the inclusion compounds 5a·18benzene and 5b·23benzene. The open frameworks of 5a·18benzene and 5b·23benzene are constructed with zeolitic or fluorite cages, and ast or flu network topology results, based on the TOPOS program. The packing of benzene molecules in 5a·18benzene and 5b·23benzene was found to be similar to that of crystals of pure benzene in edge-to-face arrangements. Thus, hydrogen-bonding networks of polyhedral organosilanols have shown selective inclusion of hydrocarbons into large cavities with adjustable porosity and without interpenetration of one network into another.

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