The average pore size and the pore size distribution of reverse osmosis membranes have been determined on the basis of the surface force-pore flow model by use of separation data of reference solutes. The results confirm the correspondence between the pore size distribution of unshrunk membranes and the shrinkage temperature profile proposed by Kunst and Sourirajan. The change in the pore size of unshrunk membranes to those of membranes shrunk at various temperatures is further related to the change in the thermodynamic properties associated with the movement of polymer molecules. The significant effect of the type of pore size distribution on the fractionation of solute molecules is also illustrated.

Odorant receptors (ORs) of ladybird Hippodamia variegata play vital chemosensory roles in searching and locating preys. In the current study, 37 ORs were initially identified from the antennal transcriptome of H. variegata. The quantitative polymerase chain reaction demonstrated that several HvarORs including HvarOR25 were specific or enriched in ladybird antennae. In two-electrode voltage clamp recordings, recombinant HvarOR25 was narrowly tuned to six chemical ligands including aphidinduced, aphid-derived, and plant-derived volatiles. In electroantennogram assays, all six volatiles elicited electrophysiological responses. Among the six volatiles, cis-3-hexenyl acetate, hexyl butyrate, hexyl hexanoate, and 3-methyl-3-buten-1-ol were attractive for both sexes of H. variegata. Additionally, molecular docking indicated that HvarOR25 was bound to all ligands with high binding affinities. Taken together, HvarOR25 facilitates perception of preys by recognizing relevant allelochemicals from hosts and habitat. Our findings provide valuable insights into understanding biological functions of HvarORs and help to develop a novel biocontrol strategy based on olfactory-active compounds.

Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) is an accurate and convenient technique for quantifying expression levels of the target genes. Selection of the appropriate reference gene is of the vital importance for RT-qPCR analysis. Hippodamia variegata is one of the most important predatory natural enemies of aphids. Recently, transcriptome and genome sequencings of H. variegata facilitate the gene functional studies. However, there has been rare investigation on the detection of stably expressed reference genes in H. variegata. In the current study, by using five analytical tools (Delta Ct, geNorm, NormFinder, BestKeeper, and RefFinder), eight candidate reference genes, namely, Actin, EF1α, RPL7, RPL18, RPS23, Tubulin-α, Tubulin-β, and TufA, were evaluated under four experimental conditions including developmental stages, tissues, temperatures, and diets. As a result, a specific set of reference genes were recommended for each experimental condition. These findings will help to improve the accuracy and reliability of RT-qPCR data, and lay a foundation for further exploration on the gene function of H. variegata.

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Reverse osmosis separations of 13 dyes were conducted by using cellulose acetate and aromatic polyamidohydrazide membranes of various average pore sizes at operating pressures in the range 689 to 1723 kPag. High performance liquid chromatography (HPLC) experiments were also performed with respect to all dyes studied using chromatography columns filled with powders of membrane polymer materials. Interfacial force constants A, B, and D, which are associated with the electrostatic force, van der Waals force, and steric hindrance, respectively, were generated by applying the transport equations to the data from reverse osmosis and HPLC experiments. These force constants enable the prediction of the dye solute separation for a given average pore radius of the membrane. This paper illustrates how the science of reverse osmosis offers a basis for the choice of membrane materials for use in reverse osmosis applications involving separation of dyes in aqueous solutions.