Search

Highlights • CRISPR/Cas9 induces random deletions in the target region of GABRR2 gene. • Both big and small indels can lead to unexpected high probability of exon truncation/skipping and exon recruitment. • It is the first observation of exon recruitment by CRISPR/Cas9-mediated GABRR2 gene editing. Abstract CRISPR/Cas9 and its variations provide an efficient tool for targeted genome editing. CRISPR/Cas9-based genome editing can induce mutations in genome that has high probability to cause exon truncation or deletion. However, screening mutations in diploid cells is difficult because of two copies of chromosome. It is an important task for determining genotypes in diploid cells subjected to editing before using these cells in gene function study. In this study, we applied CRISPR/Cas9 to edit the GABRR2 gene in mouse retinal ganglion cells to study what exactly happened in two alleles and what real mRNA isoforms formed in diploid cells. A single sgRNA was employed to generate double-strand DNA breaks. PCR sequencing was used for single clone validation in diploid cells subjected to editing. The indels and the corresponding effects at the target locus were further studied at genomic and RNA levels. We observed that CRISPR/Cas9 induces random deletions in the target region of GABRR2 gene, and both big and small indels can lead to unexpected high probability of exon truncation/skipping. In addition, random deletions in genomic region recruited introns to generate new "exon". It is the first observation of exon recruitment by CRISPR/Cas9-mediated GABRR2 gene editing. The observations may offer a reference for the future gene splicing study. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe-Kapok has been made by easy hydrothermal method. • Fe-Kapok showed Fe positive impact for As (V) removal. • High and fast As (V) adsorption. • Fe-Kapok could be regenerated and reused several times. Arsenic (As) is one of the most toxic metals for human health. In the present work, kapok fibers were modified using iron Fe(III) to enhance As(V) adsorption and then characterized using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS). The impacts of pH, dose of adsorbent, contact time, initial concentration, temperature, and coexisting ions on the adsorption of As(V) onto Fe-modified kapok fiber (Fe-kapok) surfaces were investigated. The results showed that the adsorption process fit more to the Langmuir isotherm equation and pseudo second kinetic equation, thus demonstrating that the adsorption was an endothermic, spontaneous, monolayer chemisorption process with some disorder at the solid/solution interface. The adsorption process was controlled by the film diffusion step, and the maximum adsorption capacity of Fe-kapok was calculated to be approximately 367 µg/g. Further study showed that after 8 adsorption/desorption cycles with 1 regeneration cycle, Fe-kapok was still able to remove 45% of the arsenic (100 µg/L) present in the water. A notable negative impact on the removal of As(V) from water was linked to the concentrations of SO 4 2- and PO 4 3- in the water. [ABSTRACT FROM AUTHOR]

In this contribution, we demonstrate the synthesis of hydrazone-linked COF-Paper composites (namely COF-Paper1 and COF-Paper2) constructed from two monomers of benzene-1,3,5-tricarbohydrazide (Bth) and dimethoxyterephthal-aldehyde (Dma) or 2,5-dihydroxyterephthalaldehyde (Dha) via in-situ growth method using filter paper as a matrix. Interestingly, 2D COFs paper composites display excellent luminescence in the solid-state, and the as-synthesized COF-Paper1 and COF-Paper2 can be used as turn-off fluorescence sensors to visually detect Fe3+ ions and UO 2 2+ ions by the naked eye, respectively. Moreover, the visible limit of detection for Fe3+ and UO 2 2+ was 5.6 ng cm−2 and 27 ng cm−2, respectively. XPS and FT-IR results reveal that resulting COF-Papers have significant coordination ability toward target metal ions. This effective coordination induces electron transfer from the electron-rich building module to the electron-deficient metal ion, resulting in the fluorescence quenching process. This work not only provides a methodology to grow and assemble 2D COFs into large size ensembles but also paves a new pathway for visual detection of target metal ions. • Two COF-Paper composites have been constructed via in situ growth method. • The resulting 2D COFs paper composites with excellent luminescence properties. • The synthesized COF-Papers can specifically interact with iron ions or uranyl ions. • The COF-Papers can be used as a sensor for visual detection of target metal ions. [ABSTRACT FROM AUTHOR]

Food waste and waste paper are the two largest components of municipal solid waste, and many previous studies found that their co-digestion improved methane yield. This study investigated the anaerobic co-digestion of 0–100% food waste with paper food packages on lab-scale with feedstock-to-inoculum (F/I) ratios from 0.5 to 6 (based on volatile solids, VS) and total solids contents from 8% to 28%. In addition to methane yield, volumetric productivity and process economics were also used to evaluate the operating parameters. Results showed that the highest cumulative methane yield of around 530 L/kg-VS feed was obtained from 100% food waste at F/I ratios of 0.5, 1, and 2; the highest volumetric methane productivity of 44.2 L/L work was achieved with 25% food waste at an F/I ratio of 6; and the highest annual net profit was obtained from 75% food waste at an F/I ratio of 2, which also achieved the highest internal rate of return (20.7%) and the shortest payback period (5 years). Addition of waste paper packages to food waste could enhance the digester stability, and it is beneficial to allow certain amount of paper packages and tissues to be collected together with food waste during the initial source separation. [Display omitted] [ABSTRACT FROM AUTHOR]

Mood disorders are a group of psychiatric conditions that represent leading global disease burdens. Increasing evidence from clinical and preclinical studies supports that innate immune system dysfunction plays an important part in the pathophysiology of mood disorders. P2X7 receptor, belonging to the ligand-gated ion channel P2X subfamily of purinergic P2 receptors for extracellular ATP, is highly expressed in immune cells including microglia in the central nervous system (CNS) and has a vital role in mediating innate immune response. The P2X7 receptor is also important in neuron-glia signalling in the CNS. The gene encoding human P2X7 receptor is located in a locus of susceptibility to mood disorders. In this review, we will discuss the recent progress in understanding the role of the P2X7 receptor in the pathogenesis and development of mood disorders and in discovering CNS-penetrable P2X7 antagonists for potential uses in in vivo imaging to monitor brain inflammation and antidepressant therapeutics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metal polymeric composites based on pyrimidine-functionalized COFs (covalent organic frameworks) were fabricated. • Fe@COF-Pyr composite possesses good catalytic performance for oxygen evolution reaction. • Au-Pd@COF-Pyr can promote methane oxidation. Functionalized covalent organic frameworks (COFs) materials are used in various fields due to their unique properties. Herein, the reported pyrimidine-functionalized COFs sample named COF-Pyr is selected as the matrix to provide two COFs-based metal composites Fe@COF-Pyr and Au-Pd@COF-Pyr, which are respectively synthesized through metal coordination and in situ reduction reaction. On the one hand, Fe@COF-Pyr used as the electrocatalyst exhibits a good oxygen evolution reaction activity with the overpotential of only 430 mV at a current density of 10 mA cm−2 in the KOH solution (1 M) electrolyte. It is attributed to the large specific surface area (427 m2/g) and abundant catalytic sites of Fe@COF-Pyr, which help to improve the electrochemical performance. On the other hand, Au-Pd@COF-Pyr is an excellent catalyst for methane conversion that the products of the methane oxidation reaction can be obtained under mild reaction conditions. This work not only provides a newfangled notion for the design and preparation of COFs-based metal composites but also broadens the practical application of COFs materials in the domain of catalysis. [ABSTRACT FROM AUTHOR]

Ligand-gated ion channels play a role in mediating fast synaptic transmission for communication between neurons. However, the structural basis for the functional coupling of the binding and pore domains, resulting in channel opening, remains a topic of intense investigation. Here, a series of α7 nicotinic receptor mutants were constructed for expression in cultured mammalian cells, and their single-channel properties were examined using the patch-clamp technique combined with radio ligand binding and the fluorescence staining technique. We demonstrated that the replacement of the four pore-lining residues in the channel domain of the α7 nicotinic receptor with the hydrophilic residue serine prolongs the open-channel lifetime, although the conductance of these mutants decreases. At the coupling interface between the extracellular and transmembrane domains, when the VRW residues in the Cys-loop were substituted with the corresponding residues (i.e., IYN) in the 5-HT 3A receptor, the single-channel activity elicited by acetylcholine is impaired. This effect occurred despite the expression of the mutant receptors on the cell surface and despite the fact that the apparent K d values were much lower than those of the wild-type α7 receptor. When we further lowered the channel-gating barrier of this chimera to enhance the open-channel probability, the loss of function was rescued. Overall, we explored the microscopic mechanisms underlying the interplay between the channel domains and the coupling interface that affect the channel activity, and we generated an allosteric gating model for the α7 receptor. This model shows that the gating machinery and coupling assembly codetermine the single-channel gating kinetics. These results likely apply to all channels in the Cys-loop receptor family. [ABSTRACT FROM AUTHOR]

[Display omitted] • The COF-Tr-BA was prepared for selective adsorption and Li-S battery. • COF-Tr-BA shows excellent selectivity for genistein isomer by chemical interaction. • The introduction of boric acid group helps to improve electrochemical performance. Functional triazine-based covalent organic frameworks (COFs) with boric acid units, COF-Tr-BA, are designed and synthesized via cycloaddition of imine-linked COFs, COF-Tr, with (4-ethynylphenyl) boronic acid. Owing to the chemical interaction between boric acid units and adjacent dihydroxyl groups, COF-Tr-BA is used as the adsorbent for the selective adsorption of genistein isomer 4′6,7-trihydroxyisoflavone, showing an excellent selectivity and great adsorption performance with 5.4 times adsorption capacity (67.5 mg g−1) as high as 4′5,7-trihydroxyisoflavone (12.5 mg g−1). Meanwhile, COF-Tr-BA as the sulfur host for lithium-sulfur (Li-S) battery also exhibits a better electrochemical property, giving an initial discharge capacity up to 1349 mA h g−1 and a substantial capacity of 627 mA h g−1 after 200 cycles at 0.5C. It is attributed to the sulfiphilic interaction between the introduced boric acid groups and polysulfides (PSs), as well as the lithiophilic interaction between N atoms from quinoline and triazine moieties on the backbone of COF-Tr-BA and lithium ions (Li+), thus alleviating the dissolution and reducing the shuttle effect of LiPSs. The boric acid functionalized material COF-Tr-BA with the dual-function for selective adsorption and Li-S battery proposed here lays a significant foundation for multifunctional COFs as a versatile platform in practical application. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new fluorescent covalent organic frameworks was synthesized. • N , O -bidentate ligation was be used to combine difluoroboron. • 50% B-COF exhibited red fluorescence under ultraviolet excitation. The multi-dentate chelate ligands containing N and O atoms have good chelating ability to boron trifluoride and their complexes show good fluorescence properties. In this work, a fluorescent covalent organic framework (COF) with good crystallinity and porosity, 50% B-COF, was successfully synthesized by coordination of starting COFs 50% COF-OH with boron trifluoride diethyl etherate via N, O-bidentate ligation. Imine bonds are highly polarized. The coordination of nitrogen and boron changes the electron cloud distribution of imine bonds, causing the non-fluorescent 50% COF-OH to be transformed into fluorescent 50% B-COF. 50% B-COF exhibited red fluorescence under ultraviolet excitation. This work provides a new strategy for the design of fluorescent COFs. [ABSTRACT FROM AUTHOR]