ChemInform Abstract: APPARENT MOLAL VOLUMES AND HEAT CAPACITIES OF ALKALINE EARTH CHLORIDES IN WATER AT 25 DEGREES

Die Dichten und spezifischen Wärmen der Chloride von Mg, Ca, Sr und Ba werden in Wasser bei 25°C im Konzentrationsbereich 0,01 bis 0,4m mit einem Strömungsdichtemesser und einem Strömungsmikrokalorimeter gemessen

Apparent Molal Volumes and Heat Capacities of Alkaline Earth Chlorides in Water at 25 °C

The densities and volumetric specific heats of the alkaline earth chlorides have been measured in water at 25 °C in the concentration range 0.01 to 0.4 M with a flow densimeter and a flow microcalorimeter. Apparent molal volumes and heat capacities have been derived

Apparent Molal Volumes and Heat Capacities of some Sulfates and Carbonates in Water at 25 °C

The densities and volumetric specific heats of Na2SO4, K2SO4, MgSO4, Na2CO3, NaHCO3, and NaOH were measured up to an ionic strength of 1 in water at 25 °C with a flow densimeter and a flow microcalorimeter. From these data, the heat capacity for the formation of the ion pair MgSO40was evaluated as 84.9 J K−1 mol−1. There is an anomalous increase in the apparent molal heat capacities of Na2CO3 at low concentration but the apparent molal volumes are normal. This anomaly can be suppressed with NaOH. Attempts to account quantitatively for this behavior by an hydrolysis correction were not successful

Small RNA-induced mRNA degradation achieved through both translation block and activated cleavage

Small RNA (sRNA)-induced mRNA degradation occurs through binding of an sRNA to a target mRNA with the concomitant action of the RNA degradosome, which induces an endoribonuclease E (RNase E)-dependent cleavage and degradation of the targeted mRNA. Because many sRNAs bind at the ribosome-binding site (RBS), it is possible that the resulting translation block is sufficient to promote the rapid degradation of the targeted mRNA. Contrary to this mechanism, we report here that the pairing of the sRNA RyhB to the target mRNA sodB initiates mRNA degradation even in the absence of translation on the mRNA target. Remarkably, even though it pairs at the RBS, the sRNA RyhB induces mRNA cleavage in vivo at a distal site located >350 nucleotides (nt) downstream from the RBS, ruling out local cleavage near the pairing site. Both the RNA chaperone Hfq and the RNA degradosome are required for efficient cleavage at the distal site. Thus, beyond translation initiation block, sRNA-induced mRNA cleavage requires several unexpected steps, many of which are determined by structural features of the target mRNA

Étude complémentaire

La couv. porte en outre: Planification sectorielle de l'enseignement supérieurVol.1 Analyse de la situation actuelle et éléments de prospectives -- v.2 Étude complémentaire / Antoine D'Iori