RESUMEN
Plant resource sharing mediated by mycorrhizal fungi has been a subject of recent debate, largely owing to the limitations of previously used isotopic tracking methods. Although CdSe/ZnS quantum dots (QDs) have been successfully used for in situ tracking of essential nutrients in plant-fungal systems, the Cd-containing QDs, due to the intrinsic toxic nature of Cd, are not a viable system for larger-scale in situ studies. We synthesized amino acid-based carbon quantum dots (CQDs; average hydrodynamic size 6 ± 3 nm, zeta potential -19 ± 12 mV) and compared their toxicity and uptake with commercial CdSe/ZnS QDs that we conjugated with the amino acid cysteine (Cys) (average hydrodynamic size 308 ± 150 nm, zeta potential -65 ± 4 mV) using yeast Saccharomyces cerevisiae as a proxy for mycorrhizal fungi. We showed that the CQDs readily entered yeast cells and were non-toxic up to 100 mg/L. While the Cys-conjugated CdSe/ZnS QDs were also not toxic to yeast cells up to 100 mg/L, they were not taken up into the cells but remained on the cell surfaces. These findings suggest that CQDs may be a suitable tool for molecular tracking in fungi (incl. mychorrhizal fungi) due to their ability to enter fungal cells.
RESUMEN
Fluorescent nanoparticles (FNPs) have been widely used in chemistry and medicine for decades, but their employment in biology is relatively recent. Past reviews on FNPs have focused on chemical, physical or medical uses, making the extrapolation to biological applications difficult. In biology, FNPs have largely been used for biosensing and molecular tracking. However, concerns over toxicity in early types of FNPs, such as cadmium-containing quantum dots (QDs), may have prevented wide adoption. Recent developments, especially in non-Cd-containing FNPs, have alleviated toxicity problems, facilitating the use of FNPs for addressing ecological, physiological and molecule-level processes in biological research. Standardised protocols from synthesis to application and interdisciplinary approaches are critical for establishing FNPs in the biologists' tool kit. Here, we present an introduction to FNPs, summarise their use in biological applications, and discuss technical issues such as data reliability and biocompatibility. We assess whether biological research can benefit from FNPs and suggest ways in which FNPs can be applied to answer questions in biology. We conclude that FNPs have a great potential for studying various biological processes, especially tracking, sensing and imaging in physiology and ecology.
Asunto(s)
Nanopartículas , Puntos Cuánticos , Nanopartículas/toxicidad , Reproducibilidad de los ResultadosRESUMEN
AIMS AND OBJECTIVES: Improving blood availability through voluntary or compulsory antenatal blood donation is pivotal to reducing maternal morbidity and mortality in developing countries. Willingness to donate blood is adjudged to be an important step to the actual practice of donating blood. This study aimed to determine the knowledge, attitude and willingness of men towards antenatal blood donation. PATIENTS AND METHODS: This was a descriptive cross-sectional study. A multi-stage sampling technique was used to recruit 500 married men into the study using interviewer-administered questionnaire. Data analysis was done using SPSS version 16 software package. Pearson's Chi-squared test was used to test for significant associations between variables. A P < 0.05 was considered as statistically significant. RESULTS: More than half 300 (60%) of the respondents had good knowledge of antenatal blood donation in general. Majority (85.8%) of the respondents were willing to support voluntary blood donation. The overall attitude to blood donation was positive in 77.8% of the respondents. A significantly higher proportion 268 (89.3%) of respondents with good knowledge of antenatal blood donation were willing to donate blood (P = 0.0006). CONCLUSIONS: The majority have good knowledge and positive attitude towards antenatal blood donation. However, there is need to urgently transform this positive attitude to action through continual public enlightenment to reduce maternal morbidity and mortality.