Silver nanoparticle synthesis by Acalypha wilkesiana extract: phytochemical screening, characterization, influence of operational parameters, and preliminary antibacterial testing

© 2019, The Author(s). Introduction: The application of skin bleaching products to inhibit melanogenesis is a common practice within the African diaspora. Despite the adverse health effects of skin bleaching, rigorous studies investigating skin bleaching behavior among these populations in the United States are limited. In our P30 pilot study, we explored predictors of skin bleaching practice intensity among African and Afro-Caribbean women. Methods: In collaboration with our Community Engagement Core, we conducted a cross-sectional study to investigate the relationship between demographic and psychosocial predictors and skin-bleaching-related practice patterns among African and Afro-Caribbean women in New York City. Results: Among the 76 participants recruited, the median age at the initiation of skin bleaching was 19.5 (16–25) years, yielding a median duration of 13.5 (6–23) years. Although pregnant women were not actively recruited for the study, 13.2% (n = 10) of the participants used skin bleaching products while pregnant or possibly breastfeeding. Nativeness and education were associated with various components of skin bleaching practice intensity, including duration of skin bleaching, daily use of products, and bleaching of the entire body. Participants’ perceived skin-color-related quality of life was not associated with skin bleaching practice intensity. Conclusion: Skin bleaching is a habitual practice that likely requires culturally sensitive interventions to promote behavioral change. The existence of prenatal and postnatal exposure to mercury, hydroquinone, and other potentially harmful chemicals in skin bleaching products highlights an urgent need to explore the adverse effects of skin bleaching practices on birth outcomes and the growth and neurodevelopment of young babies

BRAZILIAN ARCHIVES OF BIOLOGY AND TECHNOLOGY Characterization of Diesel Degrading Bacterial Species from Contaminated Tropical Ecosystem

ABSTRACT The bacterial diversity in a diesel contaminated tropical soil was investigated using diesel oxidation in gradient cultures dynamics (pH and OD

Influence of transition metal ion (mn4+) on mullite formation in a mixture of 50:50 Nigerian kaolin and calcined alumina

In the present investigation, 5 wt% chemical grade MnO2 was added in a mixture of 50:50 Nigerian sources of kaolin and superfine calcined alumina powder and effect of this transition metal ion on their physico-mechanical properties, phase and microstructural evolution were studied during heating in the temperature range of 1,400–1,650°C. The heated samples were found to be highly porous (>30%) in this entire temperature range. The doping of 5 wt% MnO2 in this mixture did not improved the densification, but resulted into higher flexural strength (26 MPa) at 1,400°C compared to 7 MPa in the undoped sample. At 1,650°C, the reverse trend was observed, the flexural strength of undoped sample was found to be higher (38 MPa) than doped sample (27 MPa). The XRD study revealed the formation of mullite as major and corundum as minor phases in both the samples. The microstructural study shown the presence of needle shaped mullite crystals and corundum grains. The presence of inter-granular and intra-granular pores in MnO2 doped samples might have reduced the strength at 1,650°C. The aspect ratio of mullite needle at 1,650°C was found to be higher in doped sample. The theoretical and experimental value of >4 for MnO2 ion has been validated

Combined green synthesis and theoretical study of Ag/Co nanoparticles from biomass materials

A 'green' approach which is considered safe was explored in the synthesis and theoretical analysis of bimetallic silver/cobalt nanoparticles (Ag/Co BNPs), using aqueous extract of an indigenous Canna indica (leaf part) as reducing and stabilizing agents. Optimal concentration for the synthesis was achieved by varying precursor solution concentrations at room temperature. Visual evidence of nanoparticle formation was observed by change in colour of the reaction medium. Study of the optical activity of the nanoparticles using UV-Vis spectrophotometer and photoluminescence revealed surface plasmon resonance and an intense emission, respectively. Further characterizations confirmed formation of Ag/Co BNPs using transmission electron microscopy, Fourier transfer infra-red spectroscopy and energy-dispersive X-ray spectroscopy. The optical characteristics displayed by Ag/Co BNPs is a suggestion of its possible application in colorimetric metal nanoparticle-mediated sensors, which was further corroborated by the result obtained from theoretical study