Deep Eutectic Solvents as Promising Green Solvents in Dispersive Liquid–Liquid Microextraction Based on Solidification of Floating Organic Droplet: Recent Applications, Challenges and Future Perspectives

Deep eutectic solvents (DESs) have recently attracted attention as a promising green alternative to conventional hazardous solvents by virtue of their simple preparation, low cost, and biodegradability. Even though the application of DESs in analytical chemistry is still in its early stages, the number of publications on this topic is growing. Analytical procedures applying dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFOD) are among the more appealing approaches where DESs have been found to be applicable. Herein, we provide a summary of the articles that are concerned with the application of DESs in the DLLME-SFOD of target analytes from diverse samples to provide up-to-date knowledge in this area. In addition, the major variables influencing enrichment efficiency and the microextraction mechanism are fully investigated and explained. Finally, the challenges and future perspectives of applying DESs in DLLME-SFOD are thoroughly discussed and are critically analyzed.

Combined nanopore adaptive sequencing and enzyme-based host depletion efficiently enriched microbial sequences and identified missing respiratory pathogens

Background Enzyme-based host depletion significantly improves the sensitivity of clinical metagenomics. Recent studies found that real-time adaptive sequencing of DNA molecules was achieved using a nanopore sequencing machine, which enabled effective enrichment of microbial sequences. However, few studies have compared the enzyme-based host depletion and nanopore adaptive sequencing for microbial enrichment efficiency. Results To compare the host depletion and microbial enrichment efficiency of enzyme-based and adaptive sequencing methods, the present study collected clinical samples from eight children with respiratory tract infections. The same respiratory samples were subjected to standard methods, adaptive sequencing methods, enzyme-based host depletion methods, and the combination of adaptive sequencing and enzyme-based host depletion methods. We compared the host depletion efficiency, microbial enrichment efficiency, and pathogenic microorganisms detected between the four methods. We found that adaptive sequencing, enzyme-based host depletion and the combined methods significantly enriched the microbial sequences and significantly increased the diversity of microorganisms (p value < 0.001 for each method compared to standard). The highest microbial enrichment efficiency was achieved using the combined method. Compared to the standard method, the combined method increased the microbial reads by a median of 113.41-fold (interquartile range 23.32–327.72, maximum 1812), and the number of genera by a median of 70-fold (interquartile range 56.75–86.75, maximum 164). The combined method detected 6 pathogens in 4 samples with a median read of 547, compared to 5 pathogens in 4 samples with a median read of 4 using the standard method. Conclusion The combined method is an effective, easy-to-run method for enriching microbial sequences in clinical metagenomics from sputum and bronchoalveolar lavage fluid samples and may improve the sensitivity of clinical metagenomics for other host-derived clinical samples.

n-3 LC-PUFA Enrichment Protocol for Red Earthworm, Eisenia fetida: A Cheap and Sustainable Method

This study assessed the potential of omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA) enrichment in red earthworm (Eisenia fetida, REW), via the addition of fish oil (FO, anchovy oil) to the culture-compost. FO addition to compost was tested at graded inclusion doses (0, 2.5, 5 and 10 g/100 g compost) and for different timeperiods, up to 96h. Dose, time, as well as dose and time interactions of FO compost enrichment had significant effects on all fatty acids of earthworm bodies. The enrichment with 10 g FO/100 g compost sharply increased DHA levels of the worms (14.01 mol%) within just 24 h, compared to the control group (0.92 mol%). Similar increases (ranging between 10.99 and 15.55 mol%) occurred only after 48 and 96 h in lower FO enrichment levels (2.5 and 5.0 g/100 g compost, respectively). Therefore, it was concluded that, to obtain maximum n-3 LC-PUFA enrichment efficiency in REW, an enrichment period of 24 h is ideal and recommended for the 10 g FO/ 100 g compost, whereas longer enrichment periods (48-96 h) are more suitable for lower levels of FO inclusions (2.5 or 5 g/100 g compost).

The Addition of KNO3 and (NH4)3PO4 Maybe Improves the Ability to Accumulate Cd by Regulating the Redistribution of Nutrients in Bermudagrass

The application of fertilizer can improve the Cd enrichment efficiency of plants, but the changes of nitrogen (N), phosphorus (P), potassium (K) in the growth medium have different impacts on Cd enrichment efficiency of plants. In this study, hydroponic experiment by adding different KNO3 and (NH4)3PO4 was carried out to study whether and how the addition of available N, P and K can improve Cd accumulation. The four treatments were CK, 0.4 mg kg-1 Cd (Cd), 0.4 mg kg-1 Cd and KNO3 (COK), 0.4 mg kg-1 Cd and (NH4)3PO4 (CNP). The results showed that the chlorophyll contents, PSII maximum photochemical quantum efficiency (Fv/Fm) and PSII potential activity (Fv/Fo) of COK and CNP were higher than that of CD. There was no significant difference between CK and CNP (P > 0.05). The N, P and K contents and Cd concentrations of roots and stems of COK and CNP were significantly higher than those of CD(P＜0.05).The BCF of COK and CNP were also significantly higher than that of CD, increasing by 39.8% and 37.6%, respectively. The root, stem and leaf dry weight of COK and the root and stem dry weight of CNP were higher than that of CD, and the biomass of the whole basin was significantly higher than that of CD (P＜0.05), but with no significant difference from that of CK (P＞0.05). In addition to stem K accumulation of CNP, N, P and K allocated to root and stem in COK and CNP were significantly higher than that in CD (P＜0.05). There was no significant difference in pH and water soluble Cd content among CD, COK and CNP (P＞0.05). it was concluded that plants can improve their Cd accumulation ability by changing biomass and nutrient allocation. The conclusion provides a theoretical basis for improving soil environmental factors by improving fertilization strategies of related plants so as to improve Cd enrichment ability.

Comparison and characterization of enriched mesenchymal stem cells obtained by the repeated filtration of autologous bone marrow through porous biomaterials

Background When bone marrow is repeatedly filtered through porous material, the mesenchymal stem cells (MSCs) in the bone marrow can adhere to the outer and inner walls of the carrier material to become enriched locally, and this is a promising method for MSC enrichment. In this process, the enrichment efficiency of MSCs involved in the regulation of the cell ecology of postfiltration composites containing other bone marrow components is affected by many factors. This study compared the enrichment efficiency and characterized the phenotypes of enriched MSCs obtained by the filtration of autologous bone marrow through different porous bone substitutes. Methods Human bone marrow was filtered through representative porous materials, and different factors affecting MSC enrichment efficiency were evaluated. The soluble proteins and MSC phenotypes in the bone marrow before and after filtration were also compared. Results The enrichment efficiency of the MSCs found in gelatin sponges was 96.1% ± 3.4%, which was higher than that of MSCs found in allogeneic bone (72.5% ± 7.6%) and porous β-TCP particles (61.4% ± 5.4%). A filtration frequency of 5–6 and a bone marrow/material volume ratio of 2 achieved the best enrichment efficiency for MSCs. A high-throughput antibody microarray indicated that the soluble proteins were mostly filtered out and remained in the flow through fluid, whereas a small number of proteins were abundantly (> 50%) enriched in the biomaterial. In terms of the phenotypic characteristics of the MSCs, including the cell aspect ratio, osteogenetic fate, specific antigens, gene expression profile, cell cycle stage, and apoptosis rate, no significant changes were found before or after filtration. Conclusion When autologous bone marrow is rapidly filtered through porous bone substitutes, the optimal enrichment efficiency of MSCs can be attained by the rational selection of the type of carrier material, the bone marrow/carrier material volume ratio, and the filtration frequency. The enrichment of bone marrow MSCs occurs during filtration, during which the soluble proteins in the bone marrow are also absorbed to a certain extent. This filtration enrichment technique does not affect the phenotype of the MSCs and thus may provide a safe alternative method for MSC enrichment.