Uranium is a key resource for the development of the nuclear industry, and extracting uranium from the natural seawater is one of the most promising ways to address the shortage of uranium resources. ...Herein, a semiconducting covalent organic framework (named NDA‐TN‐AO) with excellent photocatalytic and photoelectric activities was synthesized. The excellent photocatalytic effect endowed NDA‐TN‐AO with a high anti‐biofouling activity by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed UVI to insoluble UIV, thereby increasing the uranium extraction capacity. Owing to the photoinduced effect, the adsorption capacity of NDA‐TN‐AO to uranium in seawater reaches 6.07 mg g−1, which is 1.33 times of that in dark. The NDA‐TN‐AO with enhanced adsorption capacity is a promising material for extracting uranium from the natural seawater.
Photoelectric and photocatalytic effects endow the covalent organic framework NDA‐TN‐AO with good anti‐biofouling activity. This occurs by generating biotoxic reactive oxygen species and promoting photoelectrons to reduce the adsorbed UVI to insoluble UIV, thereby improving the uranium adsorption capacity.
The inherent features of covalent organic frameworks (COFs) make them highly attractive for uranium recovery applications. A key aspect yet to be explored is how to improve the selectivity and ...efficiency of COFs for recovering uranium from seawater. To achieve this goal, a series of robust and hydrophilic benzoxazole‐based COFs is developed (denoted as Tp‐DBD, Bd‐DBD, and Hb‐DBD) as efficient adsorbents for photo‐enhanced targeted uranium recovery. Benefiting from the hydroxyl groups and the formation of benzoxazole rings, the hydrophilic Tp‐DBD shows outstanding stability and chemical reduction properties. Meanwhile, the synergistic effect of the hydroxyl groups and the benzoxazole rings in the π‐conjugated frameworks significantly decrease the optical band gap, and improve the affinity and capacity to uranium recovery. In seawater, the adsorption capacity of uranium is 19.2× that of vanadium, a main interfering metal in uranium extraction.
Excellent photocatalytic activity, photothermal and photoelectric effects make Tp‐DBD produce biotoxic ROS, have good anti‐biofouling activity, and increase the adsorption rate and affinity of uranium binding sites, thereby improving the recovery capacity of uranium.
Increasing evidence suggests that long noncoding RNAs (lncRNAs) play crucial roles in various biological processes. However, little is known about the effects of lncRNAs on autophagy. Here we report ...that a lncRNA, termed cardiac autophagy inhibitory factor (CAIF), suppresses cardiac autophagy and attenuates myocardial infarction by targeting p53-mediated myocardin transcription. Myocardin expression is upregulated upon H
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and ischemia/reperfusion, and knockdown of myocardin inhibits autophagy and attenuates myocardial infarction. p53 regulates cardiomyocytes autophagy and myocardial ischemia/reperfusion injury by regulating myocardin expression. CAIF directly binds to p53 protein and blocks p53-mediated myocardin transcription, which results in the decrease of myocardin expression. Collectively, our data reveal a novel CAIF-p53-myocardin axis as a critical regulator in cardiomyocyte autophagy, which will be potential therapeutic targets in treatment of defective autophagy-associated cardiovascular diseases.
Dysregulated autophagy is associated with many pathological disorders such as cardiovascular diseases. Emerging evidence has suggested that circular RNAs (circRNAs) have important roles in some ...biological processes. However, it remains unclear whether circRNAs participate in the regulation of autophagy. Here we report that a circRNA, termed autophagy-related circular RNA (ACR), represses autophagy and myocardial infarction by targeting Pink1-mediated phosphorylation of FAM65B. ACR attenuates autophagy and cell death in cardiomyocytes. Moreover, ACR protects the heart from ischemia/reperfusion (I/R) injury and reduces myocardial infarct sizes. We identify Pink1 as an ACR target to mediate the function of ACR in cardiomyocyte autophagy. ACR activates Pink1 expression through directly binding to Dnmt3B and blocking Dnmt3B-mediated DNA methylation of Pink1 promoter. Pink1 suppresses autophagy and Pink1 transgenic mice show reduced myocardial infarction sizes. Further, we find that FAM65B is a downstream target of Pink1 and Pink1 phosphorylates FAM65B at serine 46. Phosphorylated FAM65B inhibits autophagy and cell death in the heart. Our findings reveal a novel role for the circRNA in regulating autophagy and ACR-Pink1-FAM65B axis as a regulator of autophagy in the heart will be potential therapeutic targets in treatment of cardiovascular diseases.
The type of reactions and the availability of monomers for the synthesis of sp
-c linked covalent organic frameworks (COFs) are considerably limited by the irreversibility of the C=C bond. Herein, ...inspired by the Claisen-Schmidt condensation reaction, two propenone-linked (C=C-C=O) COFs (named Py-DAB and PyN-DAB) are developed based on the base-catalyzed nucleophilic addition reaction of ketone-activated α-H with aromatic aldehydes. The introduction of propenone structure endows COFs with high crystallinity, excellent physicochemical stability, and intriguing optoelectronic properties. Benefitting from the rational design on the COFs skeleton, Py-DAB and PyN-DAB are applied to the extraction of radionuclide uranium. In particular, PyN-DAB shows excellent removal rates (>98%) in four uranium mine wastewater samples. We highlight that such a general strategy can provide a valuable avenue toward various functional porous crystalline materials.
Uranium is a key element in the nuclear industry and also a global environmental contaminant with combined highly toxic and radioactive. Currently, the materials based on post-modification of ...amidoxime have been developed for uranium detection and adsorption. However, the affinity of amidoxime group for vanadium is stronger than that of uranium, which is the main challenge hindering the practical application of amidoxime-based adsorbents. Herein, we synthesized a fluorescent covalent organic framework (TFPPy-BDOH) through integrating biphenyl diamine and pyrene unit into the π-conjugated framework. TFPPy-BDOH has an excellent selectivity to uranium due to the synergistic effect of nitrogen atom in the imine bond and hydroxyl groups in conjugated framework. It can achieve ultra-fast fluorescence response time (2 s) and ultra-low detection limit (8.8 nM), which may be attributed to its intrinsic regular porous channel structures and excellent hydrophilicity. More excitingly, TFPPy-BDOH can chemically reduce soluble U (VI) to insoluble U (IV), and release the binding site to adsorb additional U (VI), achieving high adsorption capacity of 982.6 ± 49.1 mg g−1. Therefore, TFPPy-BDOH can overcome the challenges faced by current amidoxime-based adsorbents, making it as a potential adsorbent in practical applications.
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•A fluorescent COF (TFPPy-BDOH) is synthesized by a one-step method.•TFPPy-BDOH has ultra-fast fluorescence response time for UO22+.•TFPPy-BDOH can selectively chemically reduce soluble U(VI) to insoluble U(IV).•TFPPy-BDOH achieves high sensitivity and selectivity for detecting and capturing UO22+ in harsh environments.
Porous carbons are widely used in the energy storage and conversion field because of their excellent electrical conductivity, high specific surface area and superb electrochemical stability. The ...template method is one of the most advanced approaches to prepare porous carbons with well-defined pore structures and suitable pore size distributions. The pore formation mechanism and structure-property relationships of porous carbons obtained by template methods for supercapacitor electrodes are summarized. They include hard templates (magnesium-based, silica-based, zinc-based, calcium-based templates), soft templates (conventional soft template, ionic liquids, deep eutectic solvent) and self-templates (biomass, MOFs). Furthermore, the problems in tailoring the pore texture of porous carbons are clarified, and proposals are made for future research.
We report the first example of vinylene-linked covalent organic framework (Tp-TMT) with enhanced uranium adsorption through combined selective ligand binding, chemical reduction and photocatalytic ...reduction. The dense hydroxyl functional groups on the Tp-TMT framework had good selectivity and excellent chemical reduction performance for U(VI). Meanwhile, the synergistic effect of hydroxyl groups and triazine unit significantly enhanced the photocatalytic reduction activity. Thus Tp-TMT exhibited incredible adsorption kinetics and capacity for uranium.
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•COFs effectively capture uranium through three coordinated mechanisms.•Tp-TMT has excellent visible light conversion efficiency and low band gap.•Tp-TMT enhances uranium adsorption through selective ligand binding and reduction.•Tp-TMT exhibits incredible adsorption kinetics and capacity for uranium.
So far, it remains a challenge to synthesize uranium adsorbents with robust stability, high adsorption capacity, excellent photocatalytic activity and easy regeneration. Herein, we report the first example of vinylene-linked covalent organic framework (Tp-TMT) with enhanced uranium adsorption through combined selective ligand binding, chemical reduction and photocatalytic reduction. The unique structure and excellent photocatalytic activity of Tp-TMT make it very suitable for photo-enhanced uranium adsorption through three synergistic mechanisms, thus exhibiting an outstanding uranium adsorption capacity (2362.4 mg g−1). In the dark, a large number of hydroxyl groups in the Tp-TMT framework serve as selective binding sites for uranium, and reduce part of U(VI) to U(IV), thereby greatly improving the adsorption capacity. Meanwhile, the synergistic effect of the triazine units and hydroxyl groups in the highly conjugated framework greatly decreases the optical band gap of Tp-TMT, and an additional U(VI) photocatalytic reduction process can occur under light irradiation, further increasing the adsorption kinetics and capacity. This work explored the structural and functional design of covalent organic frameworks for the adsorption and reduction of uranium in nuclear industry wastewater.
•First attempt to investigate store brand impacts on multiple-echelon supply chains.•Firms’ strategic interactions differ significantly under three-echelon channel.•Store brand can change nature of ...manufacturer-distributer strategic interaction.•Distributer may act as a buffer between manufacturer and retailer with store brand.•All channel members might even benefit from store brand introduction.
Observing that store brands are often introduced in multiple-echelon supply chains, however, the common wisdom from analytical models on store brands has been obtained from two-echelon supply chains, we investigate the strategic interaction in a three-echelon supply chain (manufacturer-distributer-retailer) with a store brand and its corresponding impacts. This research reveals the ways in which store brand affects the interaction and performance of the three-echelon supply chain, as it is significantly different from the two-echelon case. In particular, when the store brand is moderately competitive, the nature of the interaction between the national-brand manufacturer and the distributer can change from dependence to independence, enabling the national-brand manufacturer to manipulate its price leadership to increase its wholesale price instead, leaving the distributer itself to deter the SB introduction. Consequently, the distributer plays a special role as a buffer between the national-brand manufacturer and the retailer. When the store brand is competitive enough and finally introduced, all channel members may benefit from the store brand introduction, but this phenomenon never occurs in the two-echelon case under the same conditions. Therefore, this study increases our understanding of how store brand affects the multiple-echelon supply chain and provides another important theoretical explanation for why executive managers of national brand products need not overreact to the introduction of their retailers’ store brands.
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