Milli-channel array for direct and quick reading of root elongation bioassays

A novel platform to perform systematic analysis and direct reading of root elongation bioassays is presented. The device was designed to include multiplexed microenvironments for the germination and growth of individual seeds, which allows observation by the naked eye or by optical systems, notably cellphone cameras. Prototypes were fabricated by laser micromachining on a highly transparent material that is fully compatible with biological systems. The effectiveness of the milli-channel array was verified against the conventional system (Petri dish). Lactuca sativa was chosen as a model species and glyphosate as a typical toxic agent. All tests were run according to standardized procedures and data analysis was carried out through different statistical indicators such as the root elongation and germination indexes. Results attained in the milli-channel array were identical to those in Petri dish, with the remarkable benefit that several steps required in the conventional system were avoided, which enormously decreases the operation time and the possibility of experimental errors. Further advantages of the milli-channel array are also reported, such as the capability to achieve live imaging of plant organs growth through a simple experiment. The developed device has been proven to be effective, versatile, easy-to-use, and integrable to cellphones, which naturally provide facilities for data recording, analysis, and networking. These improvements open the route to novel applications of bioassays in the wide field of ecotoxicology and environmental studies.

Comparison of real-time instrument use and absorbent tube method for measuring formaldehyde in working environments: A health risk assessment for gross anatomy staff

Formaldehyde is widely used for the preservation of cadavers, exposing workers to potential risks of formaldehyde exposure in the workplace. This study compared the performance of real-time instruments (Gasmet) and absorbent tube methods in controlling formaldehyde levels in gross anatomy dissections with four working process areas. The concentrations of formaldehyde were determined over working periods ranging from 2 to 5 h. For the Gasmet results, a Monte Carlo simulation was applied in the uncertainty analysis to predict the formaldehyde concentration. Data collection involved questionnaires that included personal and work-related information. The Wilcoxon matched-pairs signed-rank test and intraclass correlation coefficients (ICC) were used to test-retest reliability between the two instruments. The results showed that the Gasmet direct reading and absorbent tube concentrations were not significantly different (p > 0.05) in all working areas and ICC was 0.939 indicating a highly reliable test result between the two measurements. The health-risk estimation indicated the hazard quotient and carcinogenic risk of formaldehyde. The carcinogenic risk was found to be unacceptable for all staff and processes, while the hazard quotient was found to be acceptable only in the body injection process. Future studies should employ a larger sample size and a greater number of sampling points to enhance the statistical power and precision of the results. The findings of this study can be used to improve work environments and develop strategies to reduce the risks for staff who work in gross anatomy dissections.