Ordered mesoporous polymers of tunable pore size from colloidal silica templates.

Ordered mesoporous polymers have been prepared by replication of colloidal crystals made from silica spheres 35 nanometers in diameter. The pores in the colloidal crystals were filled with divinylbenzene (DVB), ethyleneglycol dimethacrylate (EDMA), or a mixture of the two. Polymerization and subsequent dissolution of the silica template leaves a polycrystalline network of interconnected pores. When mixtures of DVB and EDMA are used, the pore size of the polymer replicas can be varied continuously between 35 and 15 nanometers because the polymer shrinks when the silica template is removed.

Microbial degradation of metal complexed cyanides and thiocyanate from mining wastewaters.

A microbiological examination of the soil from a cyanide wastewater storage basin was carried out. The storage basin contained water from the cyanidation process of gold extraction, and it was composed principally of simple cyanide, metal complexed cyanide, mainly cuprocyanide, ferro-ferricyanides and thiocyanate. Pseudomonas species were the principal bacteria identified in the soil. Using the storage basin soil as a seed sludge, its potential for the biodegradation of all the cyanide complexes in the mining wastewater was studied in the laboratory, using batch, fed-batch and continuous processes. The ammonia and sulphate produced were quantified. The presence of intermediate products was suspected. In the continuous process, total degradation of all cyanide was observed at a dilution rate of 0.066 day(-1).

[Embolic retinitis in Haemophilus parainfluenzae endocarditis]. / Rétinite embolique au cours d'une endocartite à Haemophilus parainfluenzae.

Infectious embolic retinopathy occurring secondary to a bacterial endocarditis is described in a 38-year-old woman with known aortic disease. The infectious organism was a haemophilus parainfluenzae confirmed by serial blood cultures and characterized by an embolic power equal to fungal infection. After four-weeks period of appropriate and intensive antibiotic therapy, blood cultures became negative but new emboli were observed in the fundus. This report describes ocular lesions rarely observed in endogenous bacterial retinitis. The delay between the bacterial endocarditis and the occurrence of the retinitis emphasizes the need for a long-term follow-up. Ophthalmologic examination can be acline for changing the heart valve.

[Isolated traumatic rupture of the membrane of Bruch complicated by choroid neovascularization]. / Rupture traumatique isolée de la membrane de Bruch compliquée de néovaisseaux choroidiens.

The authors report one case of traumatic tear in Bruch's membrane which pass close to the fovea in a thirty year old male. Sub retinal neo-vascularization arise from this choroidal rupture four months after trauma. Binocular diplopia was the first symptom of the sub-retinal neo-vascularization. It extends from the tear to involve the macula with reduction in visual acuity to 2/10eme P14. The spontaneous regression of these abnormal vessels allows to improve visual acuity to 6/10eme P2. Compared with reports in the literature, it seems that spontaneous regression of this sub-retinal neo-vascularization can be explained by the fact it grow from healty retina in young patient. There is no conclusive evidence that coagulation therapy is of any benefit in patients developing such lesions.

Isolation and study of two strains of Leptospirillum-like bacteria from a natural mixed population cultured on a cobaltiferous pyrite substrate.

Two strains of Leptospirillum-like bacteria, L6 and L8, have been isolated from a mixed inoculum, also containing Thiobacillus ferrooxidans and T. thiooxidans, cultured for one year with a colbaltiferous pyrite as energy substrate in a 100 l continuous bioleaching laboratory unit. Several physiological properties of the strains are described. The vibrio-shaped microorganisms grew at pH values lower than 1.3. Their growth rate was maximum between 2.5 and 8.0 g l1 ferrous iron. The optimal growth temperature was 37.5 degrees C. Ferric iron had a stimulative effect on bacterial development up to 8 g l-1, and growth was as rapid at 14 g l-1 ferric iron as at 8 g l-1. The negative influence of cobalt on the final cell concentration was observed at 0.5 g l-1, but the growth rate was not affected up to 2 g l-1. The G + C content of strains L8 is 55.6 mol%.