Plasmodium falciparum infection of human erythrocytes is known to result in the modification of the host cell cytoskeleton by parasite-coded proteins. However, such modifications and corresponding implications in malaria pathogenesis have not been fully explored. Here, we probed the gradual modification of infected erythrocyte cytoskeleton with advancing stages of infection using atomic force microscopy (AFM). We reported a novel strategy to derive accurate and quantitative information on the knob structures and their connections with the spectrin network by performing AFM–based imaging analysis of the cytoplasmic surface of infected erythrocytes. Significant changes on the red cell cytoskeleton were observed from the expansion of spectrin network mesh size, extension of spectrin tetramers and the decrease of spectrin abundance with advancing stages of infection. The spectrin network appeared to aggregate around knobs but also appeared sparser at non-knob areas as the parasite matured. This dramatic modification of the erythrocyte skeleton during the advancing stage of malaria infection could contribute to the loss of deformability of the infected erythrocyte.

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Boron nitride nanofibers (BNNFs) with alignment and large length have been prepared on a large scale by electrospinning the precursor fibers and subsequent nitridation. A multijet/multicollector electrospinning system is constructed by simply arranging three jets and three tip collectors abreast. By this system the aligned precursor fibers with lengths over 13 cm are collected throughout a very large length of 68 cm. The alignment of the electrospun precursor fibers is mainly induced by the converging electric field generated by the applied tip collectors. Composite B 2 O 3 /polyvinylbutyral (PVB) fibers (BOFs) were used as the precursor fibers, where PVB was added for increasing the spinnability of the electrospinning solutions. However, the presence of PVB in the BOFs results in the formation of carbon residue in the nitrided products, which is a stubborn problem for preparing the BNNFs. We successfully solved this problem by introducing a small amount of O 2 at appropriate temperature during nitridation with NH 3 . The morphology of the nitrided products is strongly dependent on the diameter and B 2 O 3 /PVB ratio of the BOFs and the BNNFs with diameters as small as below 100 nm were obtained by controlling them. The obtained BNNFs were crystallized with (002) base planes preferentially oriented in parallel to the fiber axis. A high onset oxidation temperature of 890 °C was demonstrated for the BNNFs.