Dual Colorimetric and Fluorescent Imaging of Latent Fingerprints on Both Porous and Nonporous Surfaces with Near-Infrared Fluorescent Semiconducting Polymer Dots.

Semiconducting polymer dots (Pdots) have recently been proven as a novel type of ultrabright fluorescent probes that can be extensively used in analytical detection. Here, we developed a dual visual sensor based on Pdots for fingerprint imaging. We first designed and synthesized two types of near-infrared (NIR) fluorescent polymers and then embedded ninhydrin into the Pdot matrix. The resulting Pdot assays showed the colorimetric and fluorescent dual-readout abilities to detect latent fingerprints on both porous and nonporous surfaces. The developed fingerprints clearly revealed first-, second-, and third-level details with high contrast, high selectivity, and low background interference. We also grafted the chemical groups on the nanoparticle surface to investigate the mechanisms involved in the fingerprint development processes. We further utilized this assay in note paper and checks for latent fingerprint imaging. We believe that this dual-readout method based on Pdots will create a new avenue for research in fingerprint detection and anticounterfeiting technology.

Effects of cyclic antimicrobial lipopeptides from Bacillus subtilis on growth performance, intestinal morphology, and cecal gene expression and microbiota community in broilers.

This study investigated the effects of cyclic antimicrobial lipopeptides (CLPs) from Bacillus subtilis on the growth performance, gut morphology, and cecal gene expression and microbiota in broilers; 120 1-day-old unsexed Arbor Acres chicks were randomly divided into four groups, with six replicates in each group and five broilers per cage. These groups were fed a basal diet (C), basal diet plus 10-mg enramycin/kg (E), and basal diet plus 51-mg CLPs/kg (L) or 102-mg CLPs/kg (H). The results indicated that CLP supplementation linearly increased the body weight compared with the C group at 35 days of age. Between 15 and 35 days and 1 and 35 days of age, CLP supplementation linearly increased the average daily gain compared with the C group. The duodenal villus height was significantly increased in the H group compared with the C and E groups. In the cecum, CLP supplementation linearly increased SOD and ZO-1 mRNA expression compared with the C group. ß diversity of microbiota indicated distinct clusters between the groups. CLP supplementation linearly increased the abundance of the genus Lactobacillus in the cecal digesta compared with the C group. These results demonstrate that B. subtilis-produced CLPs dose-dependently increase broilers' growth performance, improve their gut morphology, and modulate their gut microbiota.

Sulphate-activated growth of bamboo-like carbon nanotubes over copper catalysts.

A sulphate-activated mechanism is proposed to describe the growth of bamboo-like carbon nanotubes (CNTs) over copper catalysts using chemical vapour deposition with helium-diluted ethylene. Sulphate-assisted copper catalysts afford a high-yield growth of bamboo-like CNTs at a mild temperature, 800 °C; however, non-sulphate-assisted copper catalysts, e.g., copper acetate and copper nitrate prepared catalysts, were inert to CNT growth and only gave amorphous carbons (a-C) surrounding copper nanoparticles under the same conditions. Nevertheless, the addition of sulphate ions in the preparation step for the two inert catalysts can activate their abilities for CNT growth with remarkable yields. Furthermore, Raman spectra analysis demonstrates a linear dependence between the concentration of sulphate ions in copper catalysts and the ratio of CNT-a-C in the as-grown carbon soot. The sulphate-activated effect on CNT growth over copper catalysts could be related to a three-way interaction of sulphate ions, copper nanoparticles and support. In situ TEM images of an as-grown CNT irradiated by electron beams without the inlet of carbon sources reveal a new pathway of carbon diffusion through the bulk of copper nanoparticles and an enlarged inner-wall thickness of the on-site CNT. This carbon diffusion model over copper catalysts can provide new insights into the CNT growth mechanism over non-magnetic metal catalysts.