In vitro and in vivo CT imaging using bismuth sulfide modified with a highly biocompatible Pluronic F127.

Probe bismuth sulfide modified with Pluronic F127 (Bi2S3-PF127), which has high biocompatibility and dispersibility, is synthesized using triblock copolymer Pluronic F127 to modify hydrophobic Bi2S3 nanoparticles that are prepared by a hot injection method. TEM results show that most of the probe has a length of about 14.85 ± 1.70 nm and a breadth of about 4.79 ± 0.63 nm. After injected into the tail vein of a mouse, the probe has obvious CT contrast enhancement capability from x-ray CT imaging results. Meanwhile, the probe's in vivo toxicity is also studied. It is found that hematoxylin and eosin stains of major organs have no change. A biochemical analysis (alanine aminotransferase and aspartate aminotransferase) prove the probe has no adverse effects. The results of a blood analysis (white blood cell count, red blood cell count, hemoglobin, and platelet count) are also normal. The biological distribution of Bi by ICP-AES shows that most of nanoparticles are cleaned out after injection 48 h, and the circulation half-life of the probe is 5.0 h, suggesting that Bi2S3-PF127 has a long circulation and indicating that the Bi2S3-PF127 probe has good biocompatibility and safety.

RURAL LEFT-BEHIND CHILDREN ARE SERIOUSLY AFFLICTED WITH INTESTINAL HELMINTH INFECTIONS IN SOUTHERN SICHUAH, CHINA.

Rural children are seriously afflicted with intestinal helminth infections in China. Of note, the term rural children includes rural left-behind children (LBC) and rural non-left-behind children (NLBC); the difference in the prevalence of intestinal helminths between the 2 groups remains unclear. In this study, Gulin and Xuyong counties in southern Sichuan were chosen for investigation in 2019. The Kato Katz thick smear method was used to detect the presence of intestinal helminth eggs in rural children. For children aged 3-6 yr, the adhesive tape perianal swab method was used to detect Enterobius vermicularis and tapeworm eggs. Statistical differences in infection rates between the 2 groups were determined by the chi-square test. In total, 1,608 rural children, 911 LBC and 697 NLBC, participated in the investigation. Six species of intestinal helminths were detected. A total of 358 (39.3%) and 130 (18.7%) intestinal helminth positives were found among LBC and NLBC, respectively; the former had a higher (P < 0.05) infection level. Moreover, an analysis of double worm infection rates among intestinal helminth positive LBC and NLBC showed a difference between the 2 groups that was also statistically significant. These surveys indicated that the risk of intestinal helminth infection was substantially higher and the severity of infection much worse in rural LBC in southern Sichuan. More attention should be paid to the parasitic infection of LBC.

Reverse microemulsion-mediated synthesis of Bi2S3-QD@SiO2-PEG for dual modal CT-fluorescence imaging in vitro and in vivo.

Monodispersed Bi2S3-QD@SiO2-PEG nanoparticles are prepared by a one-pot method in a reverse microemulsion system, which exhibited remarkable performances in CT and fluorescence imaging in vitro and in vivo.