Reactions at the Surface of Hot Metallic FiIaments-Part V.

@IAC

Thermionic Emission and Catalytic Activity: Part III: A Mechanism of Activation of Gases at Hot Metallic Surfaces

In this paper a parallelism between thermionic emission and catalysis has been drawn

Atomic Energy and Catalyst Efficiency

This paper deals with the Atomic Energy and Catalyst Efficiency@IAC

Paradoxical microRNAs: Individual gene repressors, global translation enhancers

In mammalian cells, microRNAs regulate the expression of target mRNAs generally by reducing their stability and/or translation, and thereby control diverse cellular processes such as senescence. We recently reported the differential abundance of microRNAs in young (early-passage, proliferating) relative to senescent (late-passage, non-proliferating) WI-38 human diploid fibroblasts. Here we report that the levels of the vast majority of mRNAs were unaltered in senescent compared to young WI-38 cells, while overall mRNA translation was potently reduced in senescent cells. Downregulation of Dicer or Drosha, two major enzymes in microRNA biogenesis, lowered microRNA levels, but, unexpectedly, it also reduced global translation. While a reduction in Dicer levels markedly enhanced cellular senescence, reduction of Drosha levels did not, suggesting that the Drosha/Dicer effects on translation may be independent of senescence and further suggesting that microRNAs may directly or indirectly enhance mRNA translation in WI-38 cells. We discuss possible scenarios through which Dicer/Drosha/microRNAs could enhance translation