Novel three-dimensional fibrous covalent organic frameworks constructed via silver amalgam bridging for efficient organic dye adsorption and removal.

The construction of covalent organic frameworks (COFs) with unique structures has great significance in exploring the structure-function relationship and extending their potential applications. Fibrous COFs have demonstrated superior performance in specific application scenarios owing to the distinctive three-dimensional (3D) structure. Herein, we report a facile strategy for the fabrication of 3D COF nanofiber by exploiting silver amalgam as a bridging agent to assemble one-dimensional-extended PA-COF modules into a tubular structure. Dimensions of the obtained 3D COF nanofiber were predicted by DFT calculations, and the nanofiber was endowed with the merits of favorable uniformity and high stability. Due to the enhanced exposure of conjugatable binding sites for dye retention offered by the novel 3D architecture, the PA-COF nanofiber exhibits fast adsorption (within 5 min) and superior adsorption capacity to various organic dyes, e.g., 1717 mg g-1 for methylene blue (MB) and 978.3 mg g-1 for methyl orange (MO). Moreover, the PA-COF nanofiber shows excellent reusability in dye adsorption, which makes it a potential medium for removing dye pollutants from wastewater. This work presents an effective strategy to construct COF materials with unique architecture and potential prospects in the fields of separation and wastewater treatment.

Intraparticle and Interparticle Transferable DNA Walker Supported by DNA Micelles for Rapid Detection of MicroRNA.

Synthetic DNA walkers are artificially designed DNA self-assemblies with the capability of performing quasi-mechanical movement at the micro/nanoscale and have shown extensive promise in biosensing, intracellular imaging, and drug delivery. However, DNA walkers are usually constructed by covalently or coordinately binding DNA strands specifically to hard surfaces, thereby greatly limiting their movement efficiency. Herein, we report an intraparticle and interparticle transferable DNA walker (dynamic micelle-supported DNA walker, DM-walker) constructed by immobilizing walking tracks and walking arms onto the corona of DNA micelles according to the principle of Watson-Crick base pairing. The DNAzyme-powered walking arm can drive the intraparticle and interparticle movements of the DM-walker due to the fact that the dynamic structure of the DNA micelle helps overcome the spatial barrier between the arms and tracks in the system, resulting in high walking efficiency. Moreover, the whole DM-walker can be constructed by self-assembly, getting rid of the tedious process and low efficiency of fixing DNA strands on hard surfaces. Taking miRNA-10b as a model target, the DM-walker demonstrates high walking efficiency (reaction duration of 20 min) and high sensitivity (LOD of 87 pM). The proposed DM-walker provides an avenue to develop novel DNA walkers on dynamic interfaces and holds great potential in clinical diagnosis.

Effect of stachydrine on endoplasmic reticulum stress-induced apoptosis in rat kidney after unilateral ureteral obstruction.

Our study aimed at determining the effect of stachydrine on the PERK, CHOP, and caspase-3 in rat kidney with RIF. Rats were randomly divided into control group, model group, enalapril group, high stachydrine group, medium stachydrine group, and low stachydrine group. RIF models of five groups were developed by unilateral ureteral obstruction except the control group. The rats were sacrificed 12 days after surgery and blood samples were collected. Serum creatinine (Scr) and blood urea nitrogen (BUN) levels were detected. Renal tubular damage index was determined by HE staining. The area percentage of RIF was determined by the Masson method. Expressions of PERK, CHOP, and caspase-3 in kidney were determined by immunohistochemistry. Tubulointerstitial injury index, RIF, serum Scr, BUN level, and expressions of PERK, CHOP, and caspase-3 were different between the model and treatment groups (P < 0.05; P < 0.01). The expressions of PERK, CHOP, and caspase-3 in nephridial tissue were reduced (P < 0.05), tubulointerstitial injury and RIF were reduced (P < 0.05), and Scr and BUN were lower (P < 0.05) in the high stachydrine group than those in the enalapril group. The expressions of PERK, CHOP, and caspase-3 were reduced in the endoplasmic reticulum stress-related apoptosis pathway after stachydrine treatment. Consequently, apoptosis was prevented, and RIF was inhibited.