Spherical 2-acetylene-(copper metal-organic framework) preparation and efficient photocatalytic hydrogen evolution over combined bimetallic sulfides.

The charge density and charge transfer resistance of the assisting catalyst have a significant impact on the hydrogen evolution performance of bimetallic sulfides. However, existing mechanistic discussions often overlook the charge density between the two catalysts and whether the assisting catalyst produces enough photo-generated electrons. Here, we propose a simple method for the synthesis of 2-acetylene-(copper metal-organic frameworks) (ACu-MOFs) to improve the hydrogen evolution performance of bimetallic sulfides. Compared to copper metal-organic frameworks (Cu-MOFs), these ACu-MOFs have higher charge density and lower charge transfer resistance. More importantly, the introduction of alkyne-based Cu-MOFs further promotes the hydrogen evolution performance of bimetallic sulfides under 5 W LED light, and XPS is used to determine the difference in charge density between ACu-MOFs and Cu-MOFs and the improvement in contact electron transfer after bimetallic sulfide modification. This work mainly discusses the charge density, charge transfer resistance, and the number of photo-excited electrons generated, and provides a reasonable explanation.

Dietary Approaches to Stop Hypertension (DASH) diet, Mediterranean diet and blood lipid profiles in less-developed ethnic minority regions.

Different from developed countries, there is a paucity of research examining how the Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets relate to lipids in less-developed ethnic minority regions (LEMR). A total of 83 081 participants from seven ethnic groups were retrieved from the baseline data of the China Multi-Ethnic Cohort study, which was conducted in less-developed Southwest China between May 2018 and September 2019. Multivariable linear regression models were then used to examine the associations of the DASH and alternative Mediterranean diet (AMED) scores, assessed by modified DASH score and AMED, as well as their components with total cholesterol (TC), LDL-cholesterol, HDL-cholesterol, TAG and TC/HDL-cholesterol. The DASH scores were negatively associated with TC, HDL-cholesterol and TAG. Comparing the highest quintiles with the lowest DASH scores, TC decreased 0·0708 (95 % CI -0·0923, -0·0493) mmol/l, HDL-cholesterol decreased 0·0380 (95 % CI -0·0462, -0·0299) mmol/l and TAG decreased 0·0668 (95 % CI -0·0994, -0·0341) mmol/l. The AMED scores were negatively associated with TC, LDL-cholesterol and HDL-cholesterol. Comparing the highest quintiles with the lowest AMED scores, TC decreased 0·0816 (95 % CI -0·1035, -0·0597) mmol/l, LDL-cholesterol decreased 0·0297 (95 % CI -0·0477, -0·0118) mmol/l and HDL-cholesterol decreased 0·0275 (95 % CI -0·0358, -0·0192) mmol/l. Although both the DASH diet and the Mediterranean diet were negatively associated with blood lipids, those associations showed different patterns in LEMR, particularly for TAG and HDL-cholesterol.

Dual DNAzyme-catalytic assembly of G-quadruplexes for inducing the aggregation of gold nanoparticles and developing a novel antibiotic assay method.

By utilizing a target biorecognition reaction to induce the self-assembly of G-quadruplexes and the aggregation of gold nanoparticles (Au NPs), this work develops a novel colorimetric biosensing method for kanamycin (Kana) antibiotic detection. The compact G-quadruplex structure was assembled from its two half-split sequences which were designed in two hairpin substrates of the Mg2+-dependent DNAzyme (MNAzyme). Besides hybridizing with the aptamer strand, the MNAzyme sequence was also split into two half fragments to be designed in the two substrates. Upon the aptamer-recognition reaction toward Kana, the MNAzyme strand could be quantitatively released to cause the exposure of the split G-quadruplex-sequences on two hairpin substrate-modified Au NPs and simultaneous release of two half fragments of the MNAzyme-sequence. Thus, the K+-assisted self-folding of G-quadruplexes causes the cross-linking of the two Au NPs to realize the Au NP aggregation-based colorimetric signal output (measured at the largest absorption peak near 520 nm). Meanwhile, the self-assembled formation of the second MNAzyme drastically amplified the signal response. Under the optimal conditions, a wide linear range from 0.1 pg mL-1 to 10 ng mL-1 and an ultrahigh sensitivity with the detection limit of 76 fg mL-1 were obtained. The dose-recovery experiments in real samples showed satisfactory results with recoveries from 98.4 to 105.4% and relative errors compared with the ELISA method less than 4.1%. Due to the high selectivity, excellent repeatability and stability, and simple manipulation, this method indicates a promising potential for practical applications. A novel homogeneous biosensing method was developed for the convenient detection of the kanamycin antibiotic. The target biorecognition-induced and dual DNAzyme-catalytic assembly of G-quadruplexes enabled the amplified aggregation of gold nanoparticles for the simple, cheap, stable, and ultrasensitive colorimetric signal transduction of the method.

Supermolecule Cucurbituril Subnanoporous Carbon Supercapacitor (SCSCS).

It is quite challenging to prepare subnanometer porous materials from traditional porous precursors, and use of supramolecules as carbon sources was seldom reported due to the complex preparation and purification processes. We explore a facile one-pot method to fabricate supramolecular coordination compounds as carbon sources. The resultant CB[6]-derived carbons (CBC) have a high N content of 7.0-22.0%, surface area of 552-861 m2 g-1, and subnano/mesopores. The CBC electrodes have a narrow size distribution at 5.9 Å, and the supercapacitor exhibits an energy density of 117.1 Wh kg-1 and a potential window of over 3.8 V in a two-electrode system in the ionic liquid (MMIMBF4) electrolyte with appropriate cationic (5.8 Å) and anionic (2.3 Å) diameter. This work presents the facile fabrication of novel supermolecule cucurbituril subnanoporous carbon materials and the smart design of "pores and balls" for high-performance energy storage systems.

Morbigenous brain region and gene detection with a genetically evolved random neural network cluster approach in late mild cognitive impairment.

MOTIVATION: The multimodal data fusion analysis becomes another important field for brain disease detection and increasing researches concentrate on using neural network algorithms to solve a range of problems. However, most current neural network optimizing strategies focus on internal nodes or hidden layer numbers, while ignoring the advantages of external optimization. Additionally, in the multimodal data fusion analysis of brain science, the problems of small sample size and high-dimensional data are often encountered due to the difficulty of data collection and the specialization of brain science data, which may result in the lower generalization performance of neural network. RESULTS: We propose a genetically evolved random neural network cluster (GERNNC) model. Specifically, the fusion characteristics are first constructed to be taken as the input and the best type of neural network is selected as the base classifier to form the initial random neural network cluster. Second, the cluster is adaptively genetically evolved. Based on the GERNNC model, we further construct a multi-tasking framework for the classification of patients with brain disease and the extraction of significant characteristics. In a study of genetic data and functional magnetic resonance imaging data from the Alzheimer's Disease Neuroimaging Initiative, the framework exhibits great classification performance and strong morbigenous factor detection ability. This work demonstrates that how to effectively detect pathogenic components of the brain disease on the high-dimensional medical data and small samples. AVAILABILITY AND IMPLEMENTATION: The Matlab code is available at https://github.com/lizi1234560/GERNNC.git.

Design and Solvothermal Synthesis of Polyoxometalate-Based Cu(II)-Pyrazolate Photocatalytic Compounds for Solar-Light-Driven Hydrogen Evolution.

Polyoxometalates (POMs) are known for their photocatalytic hydrogen production activity, but their solubility and limited stability often restrict their practical applications. Herein, we designed and solvothermally synthesized two new Cu-H2bpz (3,3',5,5'-tetramethyl-4,4'-bipyrazole, abbreviated as H2bpz) compounds, namely, Cu0.5(H2bpz)(NO3) (1) and Cu(Hbpz)(Cl)·DMF (2), and three new polyoxometalate-based Cu(II)-pyrazolate compounds, namely, Cu(PW12O40)0.5(H2bpz)2(H2O)·(OH)0.5(H2O)5.5 (3), Cu(HPMo12O40)(H2bpz)2(H2O)2·(H2O)4 (4), and Cu2(SiW12O40)(H2bpz)3(H2O)3·(H2O)6 (5). Compound 3 (Cu(PW12O40)0.5(H2bpz)2(H2O)·(OH)0.5(H2O)5.5) exhibits the best photocatalytic activity of 44.4 µ L h-1 g-1, which may be related to the stability of compounds. Herein, the solvothermal method has been proven to be an effective method in synthesizing stable organic-inorganic hybrid compounds with soluble POMs, metal ions, and organic ligands. Thus, heterogeneous catalysts with outstanding solar-light-driven photocatalytic properties were obtained.

Proximity Binding-Triggered Assembly of Two MNAzymes for Catalyzed Release of G-Quadruplex DNAzymes and an Ultrasensitive Homogeneous Bioassay of Platelet-Derived Growth Factor.

When the target biorecognition-triggered assembly of two Mg2+-dependent DNAzymes (MNAzymes) is employed for dually catalytic release of peroxidase-mimicking G-quadruplex DNAzymes (G-DNAzymes), this work develops a novel homogeneous colorimetric method for an ultrasensitive bioassay of platelet-derived growth factor-BB (PDGF-BB). The first MNAzyme assembly is realized through a highly specific aptamer biorecognition-driven proximity ligation reaction. Its catalytic cleavage toward the two designed hairpin substrates not only releases a large amount of G-DNAzymes for colorimetric signal transduction but also enables the spontaneous assembly of another MNAzyme for signal amplification. This leads to the successful detection of PDGF-BB in a wide linear range from 2.0 pg mL-1 to 20 ng mL-1 with a very low detection down to 0.088 pg mL-1. As the whole reactions including aptamer biorecognitions, DNA hybridizations, and catalytic cleavages of MNAzymes are conducted in a homogeneous solution, this method has very simple manipulations and also has high repeatability. In addition, the high specificity of the aptamer biorecognition-triggered signal transduction decides the excellent selectivity of the method. This bioassay does not require an expensive instrument and nucleic acid labeling for signal readout or any nanomaterial, enzyme, or nuclease for signal amplification. Thus, it displays an extensive potential for clinical diagnostic applications.

Luminescence Tunable Europium and Samarium Complexes: Reversible On/Off Switching and White-Light Emission.

Single-molecule functional materials with luminescence tunable by external stimuli are of increasing interest due to their application in sensors, display devices, biomarkers, and switches. Herein, new europium and samarium complexes with ligands having triphenylamine (TPA) groups as the redox center and 2,2'-bipyridine (bpy) as the coordinating groups and diketonate (tta) as the second ligand have been constructed. The complexes show white-light emission in selected solvents for proper mixtures of the emission from Ln3+ ions and the ligands. Meanwhile, they exhibit reversible luminescence switching on/off properties by controlling the external potential owing to intramolecular energy transfer from the Ln3+ ions to the electrochemically generated radical cation of TPA•+. Time-dependent density functional theory (TD-DFT) calculations have been performed to study the electronic spectra. The proposed intramolecular energy transfer processes have been verified by density functional theory (DFT) studies.

Redox Chemistry of Molybdenum Trioxide for Ultrafast Hydrogen-Ion Storage.

Hydrogen ions are ideal charge carriers for rechargeable batteries due to their small ionic radius and wide availability. However, little attention has been paid to hydrogen-ion storage devices because they generally deliver relatively low Coulombic efficiency as a result of the hydrogen evolution reaction that occurs in an aqueous electrolyte. Herein, we successfully demonstrate that hydrogen ions can be electrochemically stored in an inorganic molybdenum trioxide (MoO3 ) electrode with high Coulombic efficiency and stability. The as-obtained electrode exhibits ultrafast hydrogen-ion storage properties with a specific capacity of 88 mA hg-1 at an ultrahigh rate of 100 C. The redox reaction mechanism of the MoO3 electrode in the hydrogen-ion cell was investigated in detail. The results reveal a conversion reaction of the MoO3 electrode into H0.88 MoO3 during the first hydrogen-ion insertion process and reversible intercalation/deintercalation of hydrogen ions between H0.88 MoO3 and H0.12 MoO3 during the following cycles. This study reveals new opportunities for the development of high-power energy storage devices with lightweight elements.

TiO2 Feather Duster as Effective Polysulfides Restrictor for Enhanced Electrochemical Kinetics in Lithium-Sulfur Batteries.

The rechargeable lithium-sulfur battery is recognized as a promising candidate for electrochemical energy storage system because of their exceptional advance in energy density. However, the fast capacity decay of sulfur cathode caused by polysulfide dissolution and low specific capacity caused by poor electrical conductivity still impede the further development of lithium-sulfur battery. To address above issues, this study reports the synthesis of feather duster-like TiO2 architecture by in situ growth of TiO2 nanowires on carbon cloth and further evaluates as sulfur host material. The strong chemical binding interaction between the polysulfides and TiO2 feather duster efficiently restrains the shuttle effect, leading to enhanced electrochemical kinetics. Besides, the in situ grown TiO2 NWs array also supply high surface for sulfur-loading and fast path for electron transfer and ion diffusion. As results, the novel CC/TiO2 /S composite cathode exhibits a high capacity of 608 mA h g-1 at 1.0 C after 700 cycles corresponding to capacity decay as low as 0.045% per cycle with excellent Coulombic efficiency higher than 99.5%.