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CRISPR/Cas-based systems are highly attractive for developing next-generation diagnostic technologies because of their intrinsic merits such as simplicity, sensitivity, and specificity. However, currently, nucleic acid amplification procedures are still needed to achieve attomolar sensitivity in most CRISPR/Cas-based assays, which causes high cost, operation difficulty, and low efficiency. Herein, we combine the CRISPR/Cas12a-based assay and a single-microbead detection platform for one-step and amplification-free detection of DNA at the single-molecule level. By modifying DNA reporters on a biomimetic membrane-coated microbead, the activated Cas12a by targets will cleave these reporters and lighten the bead within 10 min. The method allows the detection of the target down to three copies in a 5 μL sample. Furthermore, we successfully apply this method for the specific identification of viral infection, foodborne bacteria, and DNA mutation in real samples without extra nucleic acid amplification. We believe that this approach offers new insights for developing CRISPR/Cas-based DNA assays in biomedical applications.

Mixed matrix membranes (MMMs) were prepared by solvent evaporation method using Pebax‐1074 polymer as matrix and inorganic zeolite SAPO‐23 as dopant. The morphology, surface functional groups, microstructure, thermal stability, and separation performance of MMMs were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, and gas permeation, respectively. The effects of dopant loading amount, permeation temperature, and permeation pressure on the structure and properties of MMMs were investigated. The results showed that the introduction of SAPO zeolite reduced the crystallinity of the MMMs and improved the CO2/N2 selectivity. Under the conditions of 30°C and 0.15 MPa, the MMMs prepared by incorporating with 5% SAPO zeolite in content exhibited the highest CO2/N2 selectivity of 72.0 together with the CO2 permeability of 98.2 Barrer.

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This paper uses the Capital Asset Pricing Model and Fama-French Three-Factor Model (FF3F) to construct optimal portfolios with maximized Sharpe ratio, aiming to help retired firefighters decide between the pension’s annual benefits and the lump sum of the pension. Firstly, this paper selects six well-diversified assets from different industries. Secondly, this study estimates the expected return of each asset using the CAPM and FF3F Model, respectively. Thirdly, this paper constructs two ‘With Pension Portfolio’s using the expected return from the two models. Fourthly, this paper also builds two portfolios using the same results from the two models but keeping the pension’s weight to zero. By comparing the maximized Sharpe ratios from ‘With Pension Portfolio’s and ‘Without Pension Portfolio’s, we conclude that the firefighter should choose to take the benefits of the pension. The results in this paper can serve as a reference for retired people when they want to allocate their nest egg and pension better.