Synchronization of chaotic delayed systems via intermittent control and its adaptive strategy

In this paper the problem of synchronization for delayed chaotic systems is considered based on aperiodic intermittent control. First, delayed chaotic systems are proposed via aperiodic adaptive intermittent control. Next, to cut down the control gain, a new generalized intermittent control and its adaptive strategy is introduced. Then, by constructing a piecewise Lyapunov auxiliary function and making use of piecewise analysis technique, some effective and novel criteria are obtained to ensure the global synchronization of delayed chaotic systems by means of the designed control protocols. At the end, two examples with numerical simulations are provided to verify the effectiveness of the theoretical results proposed scheme

Fixed-Time Synchronization Control of Delayed Dynamical Complex Networks

Fixed-time synchronization problem for delayed dynamical complex networks is explored in this paper. Compared with some correspondingly existed results, a few new results are obtained to guarantee fixed-time synchronization of delayed dynamical networks model. Moreover, by designing adaptive controller and discontinuous feedback controller, fixed-time synchronization can be realized through regulating the main control parameter. Additionally, a new theorem for fixed-time synchronization is used to reduce the conservatism of the existing work in terms of conditions and the estimate of synchronization time. In particular, we obtain some fixed-time synchronization criteria for a type of coupled delayed neural networks. Finally, the analysis and comparison of the proposed controllers are given to demonstrate the validness of the derived results from one numerical example

Iodine-assisted solid-state synthesis and characterization of nanocrystalline zirconium diboride nanosheets

A solid-state route was developed to prepare zirconium diboride nanosheets with the dimension of about 500 nm and thickness of about 20 nm from zirconium dioxide, iodine and sodium borohydride at 700 °C in an autoclave reactor. The obtained ZrB₂ product was investigated by X-ray diffraction, scanning electron microscope and transmission electron microscopy. The obtained product was also studied by thermogravimetric analysis. It had good thermal stability and oxidation resistance below 400 °C in air. Furthermore, the possible formation mechanism of ZrB₂ was also discussed.Розроблено твердотільний напрямок отримання наношарів дибориду цирконію розміром ~ 500 нм і товщиною ~ 20 нм з діоксиду цирконію, йоду та боргідриду натрію при 700 °С в автоклавному реакторі. Отриманий продукт ZrB₂ досліджували рентгенівською дифракцією, скануючим електронним мікроскопом і трансмісійною електронною мікроскопією. Отриманий продукт також вивчали термогравіметричним аналізом. Він мав гарну термостійкість і стійкість до окиснення нижче 400 °C на повітрі. Крім того, обговорено також можливий механізм утворення ZrB₂.Разработан твердотельный путь получения нанослоев диборида циркония размером ~ 500 нм и толщиной ~ 20 нм из диоксида циркония, йода и боргидрида натрия при 700 °С в автоклавной реакторе. Полученный продукт ZrB₂ исследовали рентгеновской дифракцией, сканирующим электронным микроскопом и трансмиссионной электронной микроскопией. Полученный продукт также изучали термогравиметрическим анализом. Он имел хорошую термостойкость и устойчивость к окислению ниже 400 °C на воздухе. Кроме того, обсуждали также возможный механизм образования ZrB₂

ELAV/Hu RNA binding proteins determine multiple programs of neural alternative splicing.

ELAV/Hu factors are conserved RNA binding proteins (RBPs) that play diverse roles in mRNA processing and regulation. The founding member, Drosophila Elav, was recognized as a vital neural factor 35 years ago. Nevertheless, little was known about its impacts on the transcriptome, and potential functional overlap with its paralogs. Building on our recent findings that neural-specific lengthened 3' UTR isoforms are co-determined by ELAV/Hu factors, we address their impacts on splicing. While only a few splicing targets of Drosophila are known, ectopic expression of each of the three family members (Elav, Fne and Rbp9) alters hundreds of cassette exon and alternative last exon (ALE) splicing choices. Reciprocally, double mutants of elav/fne, but not elav alone, exhibit opposite effects on both classes of regulated mRNA processing events in larval CNS. While manipulation of Drosophila ELAV/Hu RBPs induces both exon skipping and inclusion, characteristic ELAV/Hu motifs are enriched only within introns flanking exons that are suppressed by ELAV/Hu factors. Moreover, the roles of ELAV/Hu factors in global promotion of distal ALE splicing are mechanistically linked to terminal 3' UTR extensions in neurons, since both processes involve bypass of proximal polyadenylation signals linked to ELAV/Hu motifs downstream of cleavage sites. We corroborate the direct action of Elav in diverse modes of mRNA processing using RRM-dependent Elav-CLIP data from S2 cells. Finally, we provide evidence for conservation in mammalian neurons, which undergo broad programs of distal ALE and APA lengthening, linked to ELAV/Hu motifs downstream of regulated polyadenylation sites. Overall, ELAV/Hu RBPs orchestrate multiple broad programs of neuronal mRNA processing and isoform diversification in Drosophila and mammalian neurons

Effect of Bone Cement Thickness on the Risk of Scalded Skin in Joint Surgery

Objective Bone cement releases a large amount of heat as it polymerizes. Skin burns caused by discarded bone cement are not well understood during arthroplasty. It is important to study the correlates and mechanisms of scalding and to accurately evaluate the severity of burns to guide treatment decisions. Methods Standardized burns were created in eight anesthetized rabbits using different thicknesses of bone cement. Bone cement was uniformly stirred to make thicknesses of 1 mm, 4 mm, 8 mm, 12 mm, 16 mm, and 20 mm and a 20 × 40 mm cuboid. Bone cement samples were then placed on the back of a rabbit, and the temperature changes were recorded with an industrial digital thermometer. One hour later, the appearance of scalded skin was observed, and the rabbits were euthanized. The scalded parts were cut to make pathological sections and stained with HE, and the differences in the depth of the scalded skin caused by different thicknesses of bone cement were observed under a light microscope. Results Damage caused by 1 mm‐, 4 mm‐, 8 mm‐, 12 mm‐, 16 mm‐, and 20 mm‐thick bone cement samples mainly involved the epidermis, the papillary dermis, the reticular dermis layer, and the full thickness of the skin and the subcutaneous tissue. The maximum temperature of 1 mm, 4 mm, 8 mm, and 12 mm bone cementation had a statistically significant difference (p < 0.001), while there was no significant difference between 12 mm, 16 mm, and 20 mm samples (p = 0.856). The time to severe scalding with bone cement at temperatures above 70°C was significantly different between different thicknesses (p < 0.001). Conclusion The heat released by different thicknesses of bone cement leads to different maximum temperatures and the duration of severe burns, resulting in different degrees of skin burns. Attention should be paid to discarded bone cement to prevent this potential complication in knee arthroplasty

Overlapping activities of ELAV/Hu family RNA binding proteins specify the extended neuronal 3' UTR landscape in Drosophila

The tissue-specific deployment of highly extended neural 3’ UTR isoforms, generated by alternative polyadenylation (APA), is a broad and conserved feature of metazoan genomes. However, the factors and mechanisms that control neural APA isoforms are not well-understood. Here, we show that three ELAV/Hu RNA binding proteins (Elav, Rbp9 and Fne) have similar capacities to induce a lengthened 3’ UTR landscape in an ectopic setting. These factors promote accumulation of chromatin-associated, 3’ UTR-extended, nascent transcripts, through inhibition of proximal polyadenylation site (PAS) usage. Notably, Elav represses an unannotated splice isoform of fne, switching the normally cytoplasmic Fne towards the nucleus in elav mutants. We use genomic profiling to reveal strong and broad loss of neural APA in elav/fne double mutant CNS, the first genetic background to largely abrogate this distinct APA signature. Overall, we demonstrate how regulatory interplay and functionally overlapping activities of neural ELAV/Hu RBPs drives the neural APA landscape