Lead-free potassium sodium niobate piezoelectric ceramics substituted with lithium and antimony (Na0.5K0.5)1−x(LiSb)xNb1−xO3 have been synthesized by conventional solid state sintering method. Compositionally engineered around the orthorhombic-tetragonal polymorphic phase transition, the dielectric and piezoelectric properties were further enhanced with the addition of lithium and antimony substituted into the perovskite structure. The combined effects of lithium and antimony additions resulted in a downward shift in the orthorhombic-tetragonal (TO-T) without significantly reducing TC. The dielectric, piezoelectric, and electromechanical properties were found to be ε∕ε0>1300, d33>260pC∕N, and kp>50%, while maintaining low dielectric loss. The enhanced polarizability associated with the polymorphic TO-T transition and high TC transition (∼390°C) should provide a wide range of temperature operation.

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The Aurivillius-type bismuth layer-structured (NaBi)0.46(LiCe)0.04Bi4Ti4O15 (NBT-LiCe) piezoelectric ceramics were synthesized using conventional solid-state processing. Phase analysis was performed by x-ray diffraction and microstructural morphology was assessed by scanning electron microscopy. The dielectric, piezoelectric, ferroelectric, and electromechanical properties of NBT-LiCe ceramics were investigated. The piezoelectric activities were found to be significantly enhanced compared to NBT ceramics, which can be attributed to the lattice distortion and the presence of bismuth vacancies. The dielectric and electromechanical properties of NBT-LiCe ceramics at elevated temperature were investigated in detail. The excellent piezoelectric, dielectric, and electromechanical properties, coupled with high Curie temperature (Tc=660 °C), demonstrated that the NBT-LiCe ceramics are the promising candidates for high temperature applications.

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High genetic diversity is thought to characterize successful invasive species, as the potential to adapt to new environments is enhanced and inbreeding is reduced. The red swamp crayfish, Procambarus clarkii, native to northeastern Mexico and southcentral USA was introduced to Nanjing, China from Japan in 1929. Little is known about the genetic diversity and population structure of this species in China. We examined the genetic diversity and population structure of six P. clarkii populations using nine polymorphic microsatellites. Among the six populations, Nanjing population showed the highest allele number, allele richness and gene diversity, which is consistent with records indicating Nanjing may be the first site of introduction. In all six populations, significant heterozygote deficit was observed, suggesting founder effects and non-random mating. Analysis of bottleneck under infinite allele model, stepwise mutation model and two-phased model of mutation revealed evidence of a recent bottleneck in all these populations. Pairwise genetic distance analysis, AMOVA and assignment tests demonstrated high genetic differentiation between populations. Pairwise genetic distance did not fit the pairwise geographic distance, suggesting that human mediated dispersal have played a role in the population expansion and genetic differentiation.

BackgroundThe Asian seabass (Lates calcarifer) is an important marine foodfish species in Southeast Asia and Australia. Genetic improvement of this species has been achieved to some extent through selective breeding programs since 1990s. Several genomic tools such as DNA markers, a linkage map, cDNA and BAC libraries have been developed to assist selective breeding. A physical map is still lacking, although it is essential for positional cloning of genes located in quantitative trait loci (QTL) and assembly of whole genome sequences.Methodology/Principal FindingsA genome-wide physical map of the Asian seabass was constructed by restriction fingerprinting of 38,208 BAC clones with SNaPshot HICF FPC technique. A total of 30,454 were assembled into 2,865 contigs. The physical length of the assembled contigs summed up to 665 Mb. Analyses of some contigs using different methods demonstrated the reliability of the assembly.Conclusions/SignificanceThe present physical map is the first physical map for Asian seabass. This physical map will facilitate the fine mapping of QTL for economically important traits and the positional cloning of genes located in QTL. It will also be useful for the whole genome sequencing and assembly. Detailed information about BAC-contigs and BAC clones are available upon request.

Aurivillius-type bismuth layer-structured ferroelectrics (BLSFs) have received significant attention for their potential use in non-volatile ferroelectric random-access memory (NvRAMs) and high-temperature piezoelectric devices, owing to their fatigue-free properties and their relatively high Curie temperature T C , respectively [1-5]. However, the piezoelectric activities in pure and modified BLSFs were found to be very low [6][7][8][9][10].Recently, we successfully prepared A-site lithium and cerium cosubstituted and B-site cobalt modified Na 0.5 Bi 4.5 Ti 4 O 15 (NBT) piezoelectric ceramics, which show superior piezoelectric properties and excellent thermal stability [11,12]. The optimal NBT piezoelectric ceramics possess a high piezoelectric coefficient d 33 of 30 pC/N and high Curie temperature T C above 650 °C. However, the piezoelectric activities for BLSF materials with higher Curie temperature, being on the order of 900 °C, were found to be inferior to that of NBT ceramics, with piezoelectric coefficient d 33 values lower than 10 pC/N. Moreover, the ultrahigh temperature (T C > 900 °C) bismuth layer-structured compounds were very rare.Calcium bismuth niobate (CaBi 2 Nb 2 O 9 , CBN) [13][14][15][16][17], which is made up of (CaNb 2 O 7 ) 2between (Bi 2 O 2 ) 2+

Background: Spinal cord injury (SCI) is a global medical problem. The smallest membrane-bound nanovesicles, known as exosomes, have a role in complex intercellular communication systems and can be used directly as therapeutic agents by acting as important paracrine factors. Nevertheless, the use of exosomes derived from BMSCs (BMSC-Exos) to treat SCI has been less, and the specific mechanism has not yet been reported. Methods: BMSC-Exos were characterized by TEM, NTA and Western blot. The effects of BMSC-Exos treatment were compared by SCI in vivo model and a series of in vitro experiments. Results: BMSC-Exos were found to enhance the expression of autophagy-related proteins LC3IIB and Beclin-1 and enabled autophagosomes formation. After BMSC-Exos treatment, there was marked decline in the level of expression of proapoptotic protein cleaved caspase-3, while that of the antiapoptotic protein Bcl-2 was upregulated. Conclusion: BMSC-Exos can attenuate neuronal apoptosis by promoting autophagy and promote the potential efficacy of functional behavior recovery in SCI rats. In summary, these findings expand the theoretical knowledge and forms a realistic route for the future treatment of SCI by BMSC-Exos.