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This study aimed to investigate the ameliorating effects of peach blossom soluble dietary fiber (PBSDF) and polyphenol (PBP) combinations on loperamide (Lop)-induced constipation in mice, together with the possible mechanism of action. The results demonstrated that the combined use of PBSDF and PBP could synergistically accelerate the gastrointestinal transit rate and gastric emptying rate, shorten first red fecal defecation time, accelerate the frequency of defecation, regulate the abnormal secretion of gastrointestinal neurotransmitters and pro-inflammatory cytokines, and down-regulate the expressions of AQP3 and AQP8. Western blotting and RT-qPCR analysis confirmed that PBSDF + PBP up-regulated the protein and mRNA expressions of SCF and C-kit in SCF/C-kit signaling pathway, and down-regulated pro-inflammatory mediator expressions in NF-κB signaling pathway. 16S rRNA sequencing showed that the diversity of gut microbiota and the relative abundance of specific strains, including Akkermansia, Bacteroides, Ruminococcus, Lachnospiraceae_NK4A136_group, and Turicibacter, rehabilitated after PBSDF + PBP intervention. These findings suggested that the combination of a certain dose of PBSDF and PBP had a synergistic effect on attenuating Lop-induced constipation, and the synergistic mechanism in improving constipation might associated with the regulating NF-κB and SCF/C-kit signaling pathway, and modulating the specific gut strains on constipation-related systemic types. The present study provided a novel strategy via dietary fiber and polyphenol interactions for the treatment of constipation.

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Mid-infrared (Mid-IR) (2-20 µm) silicon photonics has attracted much attention in the past few years due to its application potential in free-space optical communications, light detection and ranging, and molecular analysis. The grating coupler technology is one of the most widely employed approaches for light coupling between optical fibers and waveguides. In the mid-IR spectral region, due to the lack of reliable chalcogenide-fiber or ZBLAN-fiber polarization controllers, grating couplers usually suffer from huge insertion losses induced by the arbitrary polarization states of light coupled out of mid-IR fibers. As a result, it is significant to explore polarization-insensitive grating coupling techniques in mid-IR wavelengths. However, the study is currently still in its infancy. Here, we demonstrate an ultra-thin mid-IR polarization-insensitive grating coupler. The grating coupler has a maximum coupling efficiency of -11.5 dB at a center wavelength of ∼2200 nm with a 1-dB bandwidth of ∼148 nm. Compared with conventional subwavelength grating couplers, the polarization-dependent loss was improved from 9.6 dB to 2.1 dB. Moreover, we demonstrated a polarization-insensitive grating coupler at 2700-nm wavelength with a maximum coupling efficiency of -12.0 dB. Our results pave the way for the development of mid-IR photonic integrated circuits.

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AIMS: Staphylococcus aureus has emerged as a serious threat to food safety owing to biofilm formation. The study aimed to examine the antibiofilm mechanism of a novel milk-derived antimicrobial peptide BCp12 against it. METHODS AND RESULTS: Antibiofilm activity of BCp12 was studied by crystal violet staining, MTT assay, motility, SEM and CLSM. TMT proteome, real-time PCR and molecular docking in silico were conducted to evaluate the mechanism of BCp12 against S. aureus biofilm. The results showed that BCp12 had significant antibiofilm activity at 1 × MIC and sub-MIC. BCp12 induced the dispersion of structure of S. aureus biofilm BCp12 inhibited the movement of S. aureus. A total of 703 proteins were downregulated and 334 proteins were upregulated after BCp12 treatment. The proteins (agrA, agrB, agrC and psmß) of the QS systems were downregulated. Additionally, the expression of the agr-related genes, agrA, agrB, agrC and psmß, was downregulated. BCp12 was bound to the receptor proteins agrA and agrC through hydrogen bonds and π-π bonds. CONCLUSIONS: The results showed the antibiofilm activity of BCp12 and it inhibits the biofilm formation by interfering agr QS system. SIGNIFICANCE AND IMPACT OF STUDY: BCp12 has the potential to be a novel antibiofilm agent against S. aureus biofilm and used in the food industry.

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Mid-infrared (mid-IR) silicon photonics has been attracting great attention due to its tremendous potential applications in nonlinear optics, ranging, sensing, and spectroscopy. To date, mid-IR silicon devices have usually been developed based on silicon wafers with top-layer silicon thicknesses of hundreds of nanometers. Compared with the thick silicon devices, tens-of-nanometers thin silicon devices can provide giant evanescent-field energy proportions and optical mode areas, being significant for many biochemical sensing and nonlinear optics applications. However, ultra-thin mid-IR silicon devices have seldom been studied due to the difficulty of light coupling. Here, we demonstrated an ultra-thin focusing subwavelength-grating coupler for mid-IR ultra-thin suspended subwavelength-grating-cladding waveguide coupling. The results show that the grating has a maximum coupling efficiency of -7.1 dB at a center wavelength of 2200 nm with a 1-dB bandwidth of ∼115 nm and back reflection of -19.9 dB. We also measured the fiber alignment tolerance of 12 µm for 3-dB coupling efficiency reduction and bending optical loss of 0.25 dB/90°. Our results pave the way to developing mid-IR ultra-thin photonic integrated circuits.

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Development of simple and accurate methods for the detection of As3+is highly desirable and technically important. In this work, a highly sensitive and selective long-period fiber gratings sensor based on surface plasmon resonance was developed for As3+detection by designing glutathione-functionalized Au nanoparticles as a signal amplification tag. Based on the chemical interaction between As3+and glutathione, the self-assembling glutathione on the surface of the gold film combines selectively with As3+, and then anchors the glutathione-functionalized Au nanoparticles, which changes the refractive index of the surrounding environment, resulting in a shift of the transmission spectrum. Results show that the sensor could detect As3+with concentrations ranging from 0.02 to 2 ppb. The sensor exhibited excellent specificity for As3+against other metal ions, such as Na+, Fe3+, Mg2+, Cu2+, Pb2+, Ni2+, Ba2+, and Co3+. The fiber sensor was successfully employed to detect As3+in pond water samples, demonstrating that it has the potential for As3+detection with the advantages of low cost, high sensitivity, and a simple structure.