The present work studied the hormetic effect induced by uranium (U) in embryos of zebrafish (Danio rerio) using apoptosis as the biological endpoint. Hormetic effect is characterized by biphasic dose-response relationships showing a low-dose stimulation and a high-dose inhibition. Embryos were dechorionated at 4h post fertilization (hpf), and were then exposed to 10 or 100μg/l depleted uranium ...

The assembly of two-dimensional (2D) large channel uranyl-organic polyrotaxane networks as well as structural regulation of uranyl-bearing units using jointed cucurbit[6]uril-based pseudorotaxanes with integral rigidity based on supramolecular inclusion is presented for the first time. This construction strategy concerning controlling molecular integral rigidity based on supramolecular inclusio...

Spread chromatin fibers and isolated chromatin fragments prepared from chicken erythrocyte nuclei were stained with dilute aqueous uranyl acetate. High-resolution electron micrographs reveal two new morphological features exhibited by many of the chromatin nu bodies: (a) lateral association of the nu body with the connecting strand, and (b) a centrally stained spot approximately 15 A wide, poss...

Most methods for the colorimetric estimation of sodium depend upon the precipitation of the metal as sodium zinc uranyl acetate, a reaction first proposed by Barber and Kolthoff (1928). The precipitated salt, after washing, is treated in various ways to give coloured solutions. There are thus three distinct stages which have to be considered in the estimation: (1) precipitation, (2) washing of ...

In summary, the data demonstrate that, by the use of repeated injections of an iron sorbitol complex, it is possible to isolate a fraction highly enriched in hydrolytic enzymes (60 times over the homogenate) and in well preserved lysosomes emanating almost entirely from liver parenchymal cells. The advantage of adding fixative to the bottom of the gradient and of using en bloc staining with ura...

Uranium is a very toxic and radioactive element. Removal of uranium from wastewaters requires remediation technologies. Actual methods are costly and ineffective when uranium concentration is very low. Little is known about the enhancement of sorption of uranyl ions by phosphate ions on aluminosilicates. Here, we studied sorption of uranyl acetate on red clay in the presence of phosphates. The ...

Tryptic and chymotryptic light meromyosin paracrystals from red and cardiac muscles of rabbit show a negative and positive staining pattern with uranyl acetate and phosphotungstate that sharply differs from that of white muscle light meromyosin paracrystals. The main periodicity of about 430 A is the same regardless of the source of light meromyosin. The results are discussed in terms of the mo...

Sendai virus nucleocapsids have been observed by electron microscopy to coexist in three different helical pitch conformations, 5.3, 6.8, and 37.5 nm. The 5.3- and 6.8-nm conformations are present both in uranyl acetate negatively stained preparations and in tantalum-tungsten metal-shadowed preparations, whereas the 37.5-nm conformation, which has not been previously reported, is present only i...