Core-shell design of UiO66-Fe3O4 configured with EDTA-assisted washing for rapid adsorption and simple recovery of heavy metal pollutants from soil.

The coupling of washing with adsorption process can be adopted for the treatment of soils contaminated with heavy metals pollution. However, the complex environment of soil and the competitive behavior of leaching chemicals considerably restrain adsorption capacity of adsorbent material during washing process, which demands a higher resistance of the adsorbents to interference. In this study, we synthesized strongly magnetic, high specific surface area (573.49 m2/g) UiO66 composites (i.e., UiO66-Fe3O4) using hydrothermal process. The UiO66-Fe3O4 was applied as an adsorbent during the ethylene diamine tetraacetic acid (EDTA)-assisted washing process of contaminated soil. The incorporation of UiO66-Fe3O4 results in rapid heavy metal removal and recovery from the soil under low concentrations of washing agent (0.001 mol/L) with reduced residual heavy metal mobility of soil after remediation. Furthermore, UiO66-Fe3O4 can quickly recollect by an external magnet, which offers a simple and inexpensive recovery method for heavy metals from contaminated soil. Overall, UiO66-Fe3O4 configuration with EDTA-assisted washing process showed opportunities for heavy metals contaminated sites.

Control of RNA degradation in cell fate decision.

Cell fate is shaped by a unique gene expression program, which reflects the concerted action of multilayered precise regulation. Substantial research attention has been paid to the contribution of RNA biogenesis to cell fate decisions. However, increasing evidence shows that RNA degradation, well known for its function in RNA processing and the surveillance of aberrant transcripts, is broadly engaged in cell fate decisions, such as maternal-to-zygotic transition (MZT), stem cell differentiation, or somatic cell reprogramming. In this review, we first look at the diverse RNA degradation pathways in the cytoplasm and nucleus. Then, we summarize how selective transcript clearance is regulated and integrated into the gene expression regulation network for the establishment, maintenance, and exit from a special cellular state.

Simultaneous removal of NO, SO2 and Hg0 with the WDRMRS.

Micro-nanobubbles can spontaneously generate hydroxyl free radicals (OH). Urea is a cheap reductant and can react with NOx species, and their products are nontoxic and harmless N2, CO2 and H2O. In this study, a Wet Direct Recycling Micro-nanobubble Flue Gas Multi-pollutants Removal System (WDRMRS) was developed for the simultaneous removal of NO, SO2 and Hg0. In this system, a micro-nanobubble generator (MNBG) was used to produce a micro-nanobubble gas-liquid dispersion system (MNBGLS) through recycling the urea solution from the reactor and the simulated flue gas composed of N2, NO, SO2 and Hg0. The MNBGLS, which has a large gas-liquid dispersion interface, was recycled continuously from the MNBG to the reactor, thus achieving cyclic absorption of various pollutants. All of the investigated parameters, including the initial pH and temperature of the absorbent as well as the concentrations of urea, NO and SO2 had significant effects on the NO removal efficiency but did not significantly affect the SO2 removal efficiency, whereas only the initial solution pH and NO concentration affected the Hg0 removal efficiency. The analysis results of the reaction mechanism showed that ·OH played a critical role in the removal of various pollutants. After the treatment by this system, the main removal products were Hg0 sediment, SO42- and NH4+ which could be easily recycled. The use of this system (MNBGLS) for the simultaneous removal of NO, SO2 and Hg0 is a new technology application and research. Recycling process based on MNBGLS succeeded in simultaneously removing NO, SO2 and Hg0. The system (MNBGLS) can provide a reference for commercial applications. The removal products are relatively simple and beneficial to recycling, which can reduce the cost of waste gas treatment.

Comparative study on direct and indirect methods for wet desulphurisation and denitrification based on micro-nano bubbles.

The wet desulphurisation and denitrification technique based on micro-nano bubbles, which is available by either D-method or I-method, is a promising novel process. By employing piped water, Na2SO3 aqueous solution and HA-Na aqueous solution as the absorption liquids, a comparative study was conducted in this article on D-method and I-method to analyze their performance, advantages and disadvantages. It was accompanied by an investigation of how initial pH and initial temperature values of the absorption liquids affected the removal efficiency. The results suggested a positive correlation between NO/SO2 removal efficiencies and pH values but a little improvement in the removal efficiency under alkaline conditions. Furthermore, heating the absorption liquids inhibited the removal of NO and SO2. When manipulated in the same experimental environment, D-method and I-method did not present a significant difference in the SO2 removal efficiency, while the former was remarkably more effective than the latter in removing NO. To put together, D-method had higher removal efficiency, but required a large-scale micro-nano bubble generator to process a large quantity of flue gas as the micro-nano bubble generator was subject to a limited inlet flow rate. Consequently, an increase in investment and operating costs was incurred, while this issue could be avoided by I-method.

N6-Methyladenosine co-transcriptionally directs the demethylation of histone H3K9me2.

A dynamic epigenome is critical for appropriate gene expression in development and health1-5. Central to this is the intricate process of transcription6-11, which integrates cellular signaling with chromatin changes, transcriptional machinery and modifications to messenger RNA, such as N6-methyladenosine (m6A), which is co-transcriptionally incorporated. The integration of these aspects of the dynamic epigenome, however, is not well understood mechanistically. Here we show that the repressive histone mark H3K9me2 is specifically removed by the induction of m6A-modified transcripts. We demonstrate that the methyltransferase METTL3/METTL14 regulates H3K9me2 modification. We observe a genome-wide correlation between m6A and occupancy by the H3K9me2 demethylase KDM3B, and we find that the m6A reader YTHDC1 physically interacts with and recruits KDM3B to m6A-associated chromatin regions, promoting H3K9me2 demethylation and gene expression. This study establishes a direct link between m6A and dynamic chromatin modification and provides mechanistic insight into the co-transcriptional interplay between RNA modifications and histone modifications.

The RNA N6-methyladenosine modification landscape of human fetal tissues.

A single genome gives rise to diverse tissues through complex epigenomic mechanisms, including N6-methyladenosine (m6A), a widespread RNA modification that is implicated in many biological processes. Here, to explore the global landscape of m6A in human tissues, we generated 21 whole-transcriptome m6A methylomes across major fetal tissues using m6A sequencing. These data reveal dynamic m6A methylation, identify large numbers of tissue differential m6A modifications and indicate that m6A is positively correlated with gene expression homeostasis. We also report m6A methylomes of long intergenic non-coding RNA (lincRNA), finding that enhancer lincRNAs are enriched for m6A. Tissue m6A regions are often enriched for single nucleotide polymorphisms that are associated with the expression of quantitative traits and complex traits including common diseases, which may potentially affect m6A modifications. Finally, we find that m6A modifications preferentially occupy genes with CpG-rich promoters, features of which regulate RNA transcript m6A. Our data indicate that m6A is widely regulated by human genetic variation and promoters, suggesting a broad involvement of m6A in human development and disease.