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Improving the interfacial interaction between silica and rubber is always a key issue to be solved for silica‐filled rubbers. In this paper, composites are prepared by an in‐situ modification method using 1‐ethylpyridinium bromide ([EPy]Br) as the raw material, and the effect of its dosage on the interfacial interactions and macroscopic properties of silica‐filled natural rubber (NR) composites is investigated. The effect of [EPy]Br on silica dispersion and interfacial interaction between silica and NR is verified through rheological tests and calculations of glass layers. Compared with the original samples, composite performance is optimized when the usage amount is at 1phr which increases tensile strength by 5 MPa, enhances abrasion resistance by 24%, and shortens optimum curing time in half. This study is expected to provide a new strategy for improving the processability of silica‐containing composites while reducing energy consumption. Highlights: [EPy]Br enhances the interaction between rubber and filler while modifying the surface of silica.Increasing the dosage of [EPy]Br leads to a reduction in the Payne effect.The addition of [EPy]Br enhances the dispersion of silica in natural rubber.[EPy]Br significantly reduces the duration of the induction period for vulcanization.The dosage of [EPy]Br allows for controlling the mechanical properties of NR/SiO2. [ABSTRACT FROM AUTHOR]

Modern taxonomic studies of ciliated protozoa require both morphological and molecular data. One dilemma is how to distinguish morphologically similar species with few nucleotide differences in the widely used marker, the 18S rRNA gene. In the present study, two Oxytricha species were morphologically documented using light and electron microscopy. The mitochondrial cytochrome c oxidase subunit I (COI) gene and a fragment of the rRNA gene covering the 18S-ITS1-5.8S-ITS2-28S rRNA gene regions were sequenced. Phylogenetic analyses of all available Oxytricha granulifera -related populations were performed to reveal the internal relationships of this group. We described a new species, Oxytricha atypica sp. nov. , distinguished from its congeners by having seven postoral ventral cirri resulting from the additional fragmentation of anlage V during ontogenesis. Although their 18S rRNA genes differ by only one nucleotide, divergence of the COI gene is as high as 11.8% between O. atypica and the closely related species, O. granulifera. All but one of the COI nucleotide substitutions were synonymous. We documented the highly conserved nature of the 18S rRNA gene in the morphospecies of Oxytricha. Based on these findings, we speculate that O. granulifera contains cryptic species or morphospecies needing further characterization, and new insights for the taxonomy of hypotrich ciliates are also discussed. [ABSTRACT FROM AUTHOR]

Ciliates occur in the blowholes of marine mammals, but our understanding of their biology is poor. Consequently, we investigated an infestation of ciliates in an unhealthy, captive beluga whale that was exhibiting accelerated breathing, leukocytosis and expulsion of unusually large amounts of viscous sputum. This sputum contained ~104 ciliates mL-1 (when healthy, numbers were ten- to 100-fold lower). One known ciliate species, Planilamina ovata , is fully characterized, and a new species, Kyaroikeus paracetarius sp. nov. , is here described. The new species is established based on its larger number of left kineties over its only congener. Sequences of small-subunit rDNA, large-subunit rDNA and ITS1-5.8S-ITS2 regions of these two taxa were used in phylogenetic analyses, inferring that Kyaroikeus and Planilamina have close affinity with the free-living family Dysteriidae, contradicting their morphology-based assignment to the family Kyaroikeidae. We suggest that Kyaroikeidae be relegated to subfamily status. Finally, by comparing parasitic species with free-living taxa, we suggest how these ciliates have adapted to their unique environment and how they may have initially invaded the host. We provide essential data and concepts for the continued evaluation of ciliate-parasites in whale blowholes. [ABSTRACT FROM AUTHOR]

Hypotrichs are a highly differentiated and very diverse group of ciliated protists. Their systematics and taxonomy are challenging and call for detailed investigations on their general morphology, ultrastructure, ontogenesis, and molecular phylogeny. Here, a comprehensive study is conducted on a brackish water population of Parabistichella variabilis using light and electron microscopy and phylogenetic analyses based on small subunit ribosomal DNA sequence data. Its morphology, including the infraciliature, pellicle, nuclei, buccal seal, and extrusomes, is documented. The present findings indicate that in P. variabilis: (i) the cortical granules are extrusomes, which differ from those of other hypotrichs; (ii) the buccal seal is bounded by the plasma membrane and contains a single layer of longitudinal microtubules; (iii) two contractile vacuoles might be present rather than one; and (iv) the pharyngeal disks are bounded by a single membrane. Early‐to‐middle stages of ontogenesis are described for the first time, enabling the complete characterization of this process. Phylogenetic analyses indicate that Parabistichella variabilis is closely related to several species from different genera, such as Orthoamphisiella breviseries, Uroleptoides magnigranulosus, and Tachysoma pellionellum. However, ultrastructural and gene sequence data for more taxa are needed in order to resolve the systematics of Parabistichella. [ABSTRACT FROM AUTHOR]