No abstract

Organosilane-functionalized carbon dots (SiC-dots) were prepared by a simple one-pot hydrothermal approach. The photoluminescence (PL) properties of the SiC-dots revealed a reversible response toward the temperature (293-343 K). Through Si-O-Si bonding, temperature-sensitive PL SiC-dot films could be easily fabricated on glass substrates.

A facile, one-pot synthetic approach has been developed for the preparation of BSA-Ce/Au NCs. The fluorescence intensities of BSA-Ce/Au NCs at 410 and 650 nm are pH dependent and independent, respectively. The fluorescence intensity ratio (I410/I650) is linear against pH values from 6.0 to 9.0. These stable and biocompatible BSA-Ce/Au NCs have been used as ratiometric probes for monitoring local pH values inside HeLa cells.

A simple, sensitive, and selective fluorescence assay for the detection of CN(-) has been demonstrated using bovine serum albumin-stabilized cerium/gold nanoclusters (BSA-Ce/Au NCs). When excited at 325 nm, BSA-Ce/Au NCs have two fluorescence bands centered at 410 and 658 nm, which are assigned to BSA-Ce/Au complexes and Au NCs, respectively. Each BSA-Ce/Au NC contains 22 Au atoms and 8 Ce ions. Through etching of the Au core in BSA-Ce/Au NCs by CN(-), the fluorescence at 658 nm is quenched, while that at 410 nm enhances during the formation of complexes among BSA, Ce(4+), and [Au(CN)2](-). The circular dichroism spectra reveal that relative to BSA-Au NCs, BSA-Ce/Au NCs have looser structures of the BSA templates. As a result, it is easier for CN(-) to access the Au cores in BSA-Ce/Au NCs, allowing faster (within 15 min) etching of the Au cores by CN(-). At pH 12.0, this assay allows the detection of CN(-) down to 50 nM, with linearity over 0.1-15 μM. This assay has been applied to the determination of the concentrations of CN(-) in spiked drinking water and pond water samples.

The ATPsyn-b encoding for subunit b of ATP synthase in Drosophila melanogaster is proposed to act in ATP synthesis and phagocytosis, and has been identified as one of the sperm proteins in both Drosophila and mammals. At present, its details of functions in animal growth and spermatogenesis have not been reported. In this study, we knocked down ATPsyn-b using Drosophila lines expressing inducible hairpin RNAi constructs and Gal4 drivers. Ubiquitous knockdown of ATPsyn-b resulted in growth defects in larval stage as the larvae did not grow bigger than the size of normal second-instar larvae. Knockdown in testes did not interrupt the developmental excursion to viable adult flies, however, these male adults were sterile. Analyses of testes revealed disrupted nuclear bundles during spermatogenesis and abnormal shaping in spermatid elongation. There were no mature sperm in the seminal vesicle of ATPsyn-b knockdown male testes. These findings suggest us that ATPsyn-b acts in growth and male fertility of Drosophila.