Biodegradable Biomaterials as Suitable Alternatives to Water Treatment Technologies

Nitrates and phosphates are essential nutrients for plants growth. Their excess presence in water, however, could cause eutrophication affecting the water quality and altering the aquatic ecosystem. Algal blooms and the presence of toxins such as microcystin in freshwater bodies are hazardous to humans, animals, and wildlife. Conventional technologies such as ion exchange, distillation, reverse osmosis, and bioreactors aid immensely to remove nutrients; however, they are expensive. Furthermore, building new nitrate and phosphate treatment units, maintenance and post-disposal are costly too. In this regard, there exists an unmet need for alternative processes that are renewable and cost-effective to treat contaminated water. Herein, a novel opportunity based on inexpensive and widespread polysaccharides, e.g. alginate, has been developed to capture nitrate and phosphate from water and improving water quality. Alginate beads have been prepared in the presence of divalent (Ca2+, Fe2+, Ni2+, Cu2+, Zn2+, and Sr2+) and trivalent (Al3+ and Fe3+) cations. The maximum absorption capacity of nitrate and phosphate by the alginate beads has been established using 5, 10, 25 mg/L of nitrate and 1, 5, 10, 15, and 20 mg/L of phosphate solutions. Results suggest that alginate beads are effective to capture nitrate and phosphate from solutions and the type of ionic crosslink ions has a significant influence on the total absorbed amount. A maximum (94.0 ±0.1)% of phosphate could be removed using the Al3+-alginate beads and (33.6±1.9)% of nitrates by the Fe3+-alginate beads. Further characterization of beads by FTIR and DSC reveal the influence of ions on the nitrate and phosphate absorption capacity by the alginate beads. Overall, this study successfully establishes the potential of polysaccharide beads to capture nutrients and improve water quality and opens a new window of opportunities to water treatment technologies

The Roles of DUXA, DPRX, and ARGFX Genes on Human Preimplantation Embryo Development

In mammals, pre-implantation embryo development (PED) encompasses the time from the fertilization to the placement of blastocyst in the uterus. This period of development goes through dynamic cellular and molecular changes essential for pregnancy. Key regulatory networks for human PED remain unclear. Advances in sequencing technologies allow us to detect molecular signatures of individual cells during PED. We have performed bioinformatic analyses on existing single-cell RNA-sequencing (scRNA-seq) datasets to understand the dynamic gene expression during PED. Analysis of expression profiling of 7500 most changed genes indicated that PRD-like homeobox proteins have a significant impact on the regulation of gene expression during PED. Out of nine PRD-like homeodomain encoding transcription factors (TFs), we have found significant and dynamic expression pattern of three PRD-like TFs (DUXA, DPRX, and ARGFX). Based on clustering analysis, we found significant upregulation of these three genes after 4-cell stage before reducing by the end of morula stage. Tissue-specific expression analysis revealed that our interested genes (DUXA, DPRX, and ARGFX) showed a higher level of expression in the reproductive tissue like testis. We found 18.5% to 27.7% similarity in protein sequences of this three TFs indicating that PRD-class homeodomain has similar characteristics. Phylogenetic analysis of all eleven classes of homeodomain TFs indicated that DUXA, DPRX, and ARGFX located in the PRD-class. Using Ensembl Genome Browser and NCBI database for Entrez Gene we found 11 DUXA pseudogenes, 7 DPRX and 2 ARGFX pseudogenes in human. Chi-squared test with a p-valu

Effects of long-term chlorpyrifos exposure on mortality and reproductive tissues of Banded Gourami (Trichogaster fasciata)

This study assessed the long-term toxicity of chlorpyrifos on survival and reproduction of Banded Gourami by using mortality, gonado-somatic index (GSI) and histopathological observations as endpoints. Adult fish were exposed to five different concentrations of chlorpyrifos (0, 15, 50, 150, 500 µg/L) in 15 PVC tanks for 15, 30, 45, 60 and 75 days. Results showed that all male and female fish died after 15 days of 500 µg/L chlorpyrifos exposure. No consistent significant effect was observed for both male and female GSI. Furthermore, results showed dose- and time-dependent histopathological alterations for both ovary and testes. The 60-d No Observed Effect Concentration (NOEC) for most histopathological alterations of Banded Gourami ovary and testes was 50 μg/L, while 60-d NOEC for mortality of both male and female fish was < 15 μg/L. The results show that the long-term exposure to chlorpyrifos not only affect the reproductive tissues of Banded Gourami at exposure concentrations but also cause their mortality. Future studies should evaluate effects at lower concentrations.</p