Antennal sensilla of the ground beetle Bembidion properans Steph. (Coleoptera, Carabidae)

The arrangement of antennal sensilla was studied in female and male ground beetles Bembidion properans Steph. (Coleoptera, Carabidae) using scanning electron microscopy. The filiform antennae, 1.8-1.9 mm in length, consist of the scape, pedicel and nine flagellomeres. In both sexes, three types of sensilla chaetica, two types of sensilla trichodea, six types of sensilla basiconica, one type of sensilla coeloconica and one type of sensilla campaniformia were distinguished. The possible function of the sensilla is discussed and three types of sensilla are considered olfactory, sensilla trichodea type 2 and sensilla basiconica types 1 and 2. Olfactory sensilla form dorsal and/or ventral sensillar fields on the flagellomeres and occur sparsely or not at all outside these areas. No sexual differences in the types, number and distribution of antennal sensilla were found.     

Impact of Thermal Treatment on the Starch-Protein Interplay in Red Lentils: Connecting Molecular Features and Rheological Properties

Thermal treatments are widely applied to gluten-free (GF) flours to change their functionality. Despite the interest in using pulses in GF formulations, the effects of thermal treatment at the molecular level and their relationship with dough rheology have not been fully addressed. Raw and heat-treated red lentils were tested for starch and protein features. Interactions with water were assessed by thermogravimetric analysis and water-holding capacity. Finally, mixing properties were investigated. The thermal treatment of red lentils induced a structural modification of both starch and proteins. In the case of starch, such changes consequently affected the kinetics of gelatinization. Flour treatment increased the temperature required for gelatinization, and led to an increased viscosity during both gelatinization and retrogradation. Regarding proteins, heat treatment promoted the formation of aggregates, mainly stabilized by hydrophobic interactions between (partially) unfolded proteins. Overall, the structural modifications of starch and proteins enhanced the hydration properties of the dough, resulting in increased consistency during mixing.     

A regio- and stereoisomeric study of allylic alcohol fluorination with a range of reagents

A range of dehydroxyfluorination reagents was reacted with separate diastereoisomers of a chiral allylic alcohol to explore both the regio- and stereoselectivity ratios of direct versus allylic fluorination. The allylic alcohol stereoisomers gave the same predominant fluorinated diastereoisomer indicating that the reaction proceeds with a significant S_N1 component via an allylic carbocation intermediate, which is quenched by fluoride ion, predominantly from the least hindered face. None of the reagents displayed very high regio- or stereoselectivity, although in all cases the allylic fluorination products predominated.     

Impact of rock fabric,thermal behavior,and carbonate decomposition kinetics on quicklime industrial production and slaking reactivity

This paper deals with thermal analyses, burning trials and reactivity tests on 15 carbonate rocks, i.e., pure and impure carbonates, mud-supported and grain-supported limestones, crystalline marbles, and dolomites, used for the production of different lime products in industrial vertical shaft kilns worldwide. In particular, thermogravimetric and differential thermogravimetric analysis (TG–DTG) on massive (80–120 g) fine-grained (< 3.35 mm) samples allowed the extrapolation of the Arrhenius kinetic parameters, i.e., the (apparent) activation energy (E_a) and the pre-exponential or frequency factor (A). Other calcination parameters, i.e., the duration time, starting and ending calcination times and temperatures, and peaks of maximum calcination rate were also extrapolated in order to enhance their relationships with quicklime reactivity. Moreover, thermal analyses (TG–DTG–DTA) were repeated on powders (90 mg) using a more accurate analyzer to compare results. The study is completed by a thorough chemical–physical and mineralogical–petrographic characterization of carbonate rocks and derived burnt products. Results pointed out that medium-to-coarse crystalline materials, i.e., grain-supported limestones, diagenetic dolomites, and granoblastic marbles presented the highest activation energy, burnability and slaking reactivity. Conversely, microcrystalline carbonates with the highest micrite-to-sparite ratio, i.e., mud-supported limestones, and impure carbonates, enriched in quartz, clay minerals, and other subordinated non-carbonate impurities, presented the lowest activation energy, burnability, and slaking reactivity. This study also investigated the effect of BET-specific surface area and real density, depending on specific sintering tendency, on quicklime reactivity. Results from this multidisciplinary research activity put further constraints on carbonate rocks calcination kinetics and their suitability in the lime industry.

     

Stereospecific benzylic dehydroxyfluorination reactions using Bio’s TMS-amine additive approach with challenging substrates

Reactions involving the conversion of a benzylic alcohol into a benzylic fluoride using RSF₃ reagents are notoriously difficult to achieve with high stereochemical inversion (S_N2 reaction) due to competing dissociative S_N1 reaction processes. This Letter develops the methodology of Bio et al., and reports that the addition of a preformed 1:TMS-amine 1:RSF₃ (fluorination reagent) complex as the reagent in these reactions significantly suppresses the S_N1 process and promotes a highly stereospecific reaction generating benzylic fluorination products of high %ee.