Eight three-dimensional lanthanide-organic frameworks: [Ln(BPDC)1.5(DMF)(H2O)2]·2H2O (Ln = Eu (1), Gd (2), Tb (3), Dy (4); BPDC = 4,4'-dicarboxylate-2,2'-dipyridine anion), [Ln(BPDC)(DMF)2(NO3)] (Ln = Eu (5), Gd (6), Tb (7), Dy (8)) were fabricated and structurally characterized. Compounds 1-4 are isostructural, belonging to the triclinic system with space group P1¯, while compounds 6-8 belong to the monoclinic system with space group C2/c. Structural differences between two types of compounds may be caused by different reaction conditions. Magnetic properties of 2-4 and 6-8 have been investigated and only compounds 4 and 8 display significant frequency-dependence, albeit without reaching the characteristic maxima above 2 K, implying slow magnetic relaxation behaviors in 4 and 8. After the application of a DC field, good peak shapes of AC signal were obtained and got the energy barrier for 4, ΔE/kB = 79.80 K and the pre-exponential factor τ0 = 1.28 × 10(-10) s, for 8, ΔE/kB = 38.15 K and τ0 = 2.47 × 10(-9) s. Geometrical differences in the crystal fields of Dy(3+) in 4 and 8 seem to be responsible for the large divergence of their magnetic behaviors. Luminescence analyses were performed on coordination polymers containing Eu(3+), Tb(3+), and Dy(3+), which exhibit the characteristic transitions of corresponding lanthanide ions, and give the lifetime (τ0) of 1, 3, 4, 5, 7 and 8 are 0.56 ms, 0.89 ms, 8.48 μs, 0.60 ms, 0.75 ms and 36.35 μs, respectively.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Electrolytic hydrogen generation needs earth-abundant oxygen evolution reaction electrocatalysts that perform efficiently at mild pH. Here, the development of amorphous nickel-cobalt-borate nanosheet arrays on macroporous nickel foam (NiCo-Bi/NF) as a 3D catalyst electrode for high-performance water oxidation in near-neutral media is reported. To drive a current density of 10 mA cm-2 , the resulting NiCo-Bi/NF demands an overpotential of only 430 mV in 0.1 m potassium borate (K-Bi, pH 9.2). Moreover, it also shows long-term electrochemical durability with maintenance of catalytic activity for 20 h, achieving a high turnover frequency of 0.21 s-1 at an overpotential of 550 mV.
We describe a simple aptamer assay for the rapid analysis of aflatoxin B1 (AFB1), a potently carcinogenic fungal metabolite. The original anti-AFB1 aptamer was rationally truncated, obtaining a short aptamer that displayed better performance. Different concentrations of AFB1 were detected by measuring the circular dichroism spectra of this short aptamer. The detection limit reached 0.6 nM, which was lower than that of the original aptamer (80 nM).
As the first barrier of radioactivity in the reactor core, Zr alloy nuclear fuel rods are easily to be scratched by the fixed skeleton during installation process. In order to protect them from possible damage during their insertion with the skeleton, it is proposed to use water-soluble coatings with excellent scratch resistance to protect nuclear fuel rods. In this study, polyacrylate emulsion, neutralizer and filler were used to synthesize the coating. The chemical composition and thermal stability and hydrophilic performance of the coating were verified by Fourier Transform Infrared Spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and water contact angle (WCA). TGA analysis shows that the weight loss rate of the coating was less than 10% at 200 °C, indicating that the coating had good thermal stability below 200 °C. The water contact Angle of the coating was reduced from 66.21° to 32.78° after adding neutralizer and filler, indicating that the coating had better hydrophilicity. Scanning electron microscopy showed that the coating structure was denser and had better scratch resistance after adding neutralizer and filler. By adjusting the curing conditions, the optimized preparation parameters of the coating were obtained. When the curing temperature was 90 °C and the curing time was 30 min, the coating had more optimized scratch resistance and water solubility.
We propose a DNAzyme walker constructed from aptamer-modified DNA nanowires, which can efficiently penetrate target cells without the assistance of non-DNA substances. This strategy enables sensitive and effective imaging of miRNA in tumor cells.
Multicompartment nanoparticles (MCBNs) constructed with the brush block terpolymer of [poly(p-chloromethylstyrene)-graft-poly(4-vinylpyridine)]-block-polystyrene (PCMS-g-P4VP)-b-PS are prepared through dispersion polymerization of styrene in the methanol/water mixture mediated by the brush macro-RAFT agent of poly(p-chloromethylstyrene)-graft-poly(4-vinylpyridine) trithiocarbonate. During the dispersion RAFT polymerization, the molecular weight of the brush (PCMS-g-P4VP)-b-PS block terpolymer linearly increases with the monomer conversion. Ascribed to the brush (PCMS-g-P4VP) block, MCBNs including a PS core and discrete subdomains of (PCMS-g-P4VP) on the PS core dispersed in water are formed. The reasons leading to formation of MCBNs are discussed, and the immiscibility of the brush (PCMS-g-P4VP) block with the PS core, the low number density of the brush (PCMS-g-P4VP25)21 chains tethered on per surface area of the PS core, and the high molecular weight but the low polymerization degree of the brush (PCMS-g-P4VP) block are ascribed. Au nanoparticles are immobilized on the bulgy PCMS-g-P4VP subdomains on MCBNs and show high catalytic efficiency in the aerobic alcohol oxidation.
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