Short-Chain Fatty Acids Alleviate Vancomycin-Caused Humoral Immunity Attenuation in Rabies-Vaccinated Mice by Promoting the Generation of Plasma Cells via Akt-mTOR Pathway.

Mounting evidence suggests that gut microbial composition and its metabolites, including short-chain fatty acids (SCFAs), have beneficial effects in regulating host immunogenicity to vaccines. However, it remains unknown whether and how SCFAs improve the immunogenicity of the rabies vaccine. In this study, we investigated the effect of SCFAs on the immune response to rabies vaccine in vancomycin (Vanco)-treated mice and found that oral gavage with butyrate-producing bacteria (C. butyricum) and butyrate supplementation elevated RABV-specific IgM, IgG, and virus-neutralizing antibodies (VNAs) in Vanco-treated mice. Supplementation with butyrate expanded antigen-specific CD4+ T cells and IFN-γ-secreting cells, augmented germinal center (GC) B cell recruitment, promoted plasma cells (PCs) and RABV-specific antibody-secreting cells (ASCs) generation in Vanco-treated mice. Mechanistically, butyrate enhanced mitochondrial function and activated the Akt-mTOR pathway in primary B cells isolated from Vanco-treated mice, ultimately promoting B lymphocyte-induced maturation protein-1 (Blimp-1) expression and CD138+ PCs generation. These results highlight the important role of butyrate in alleviating Vanco-caused humoral immunity attenuation in rabies-vaccinated mice and maintaining host immune homeostasis. IMPORTANCE The gut microbiome plays many crucial roles in the maintenance of immune homeostasis. Alteration of the gut microbiome and metabolites has been shown to impact vaccine efficacy. SCFAs can act as an energy source for B-cells, thereby promoting both mucosal and systemic immunity in the host by inhibiting HDACs and activation of GPR receptors. This study investigates the impact of orally administered butyrate, an SCFA, on the immunogenicity of rabies vaccines in Vanco-treated mice. The results showed that butyrate ameliorated humoral immunity by facilitating the generation of plasma cells via the Akt-mTOR in Vanco-treated mice. These findings unveil the impact of SCFAs on the immune response of the rabies vaccine and confirm the crucial role of butyrate in regulating immunogenicity to rabies vaccines in antibiotic-treated mice. This study provides a fresh insight into the relationship of microbial metabolites and rabies vaccination.

Nurse practice environment, perceived organizational support, general well-being, occupational burnout and turnover intention: A moderated multi-mediation model.

AIMS: To test the relationship between practice environment and turnover intention, considering the moderation of perceived organizational support (POS) and the mediation of general well-being (GWB) and occupational burnout (OB) among the nurse population. DESIGN: A cross-sectional survey design. METHODS: Based on a sample of 474 nurses from two hospitals between May 2020 and September 2021, a moderated multi-mediation model was tested in which GWB and OB served as two mediators between practice environments and nurses' turnover intention, and POS was regarded as a moderator between practice environments and GWB. RESULTS: This current study supported a moderated multi-mediation model where the relationship between practice environment and turnover intention (B = 0.33, p < 0.001) was mediated by GWB (B = 0.17, p < 0.001) and OB (B = 0.18, p < 0.001), and POS moderated the effect of practice environment and GWB (B = 0.19, p < 0.001). PUBLIC CONTRIBUTION: The findings of this study can inform the design of effective organizational support and meet nurse emotional needs programmes to reduce the turnover intention among nurses.

Delay-disorder fiber Bragg grating recognition and calibration method for a Fourier domain mode-locked wavelength-swept laser-based interrogation system.

Fourier domain mode-locking has been used in fiber Bragg grating interrogation for high-speed and long-distance measurement. But the delays induced by long fiber between multisensors and interrogation systems result in nonneglected wavelength error in this high-speed wavelength-swept system. More seriously, the cross-sweep cycle and different distance delays may cause the delay-disorder problem which makes the system unable to determine the order of the delayed peaks and unable to address the location of sensors with corresponding wavelength-encoding characteristics. This paper proposes a novel delayed-peak recognition and calibration method in which the laser works at four different scanning rates. We confirm the relationship between delayed peaks and sensors with recognition parameters at two low rates and eliminate wavelength error at two high rates. Experimental results show that this method recognizes the delayed peaks correctly and calibrates wavelength accurately with error below 10 pm.

Effects of dentifrice containing hydroxyapatite on dentinal tubule occlusion and aqueous hexavalent chromium cations sorption: a preliminary study.

In order to endow environmental protection features to dentifrice, hydroxyapatite (HA) was added to ordinary dentifrice. The effects on dentinal tubule occlusion and surface mineralization were compared after brushing dentine discs with dentifrice with or without HA. The two types of dentifrice were then added to 100 µg/ml of hexavalent chromium cation (Cr(6+)) solution in order to evaluate their capacities of adsorbing Cr(6+) from water. Our results showed that the dentifrice containing HA was significantly better than the ordinary dentifrice in occluding the dentinal tubules with a plugging rate greater than 90%. Moreover, the effect of the HA dentifrice was persistent and energy-dispersive spectrometer (EDS) revealed that the atomic percentages of calcium and phosphorus on the surface of dentine discs increased significantly. Adding HA to ordinary dentifrice significantly enhanced the ability of dentifrice to adsorb Cr(6+) from water with the removal rate up to 52.36%. In addition, the sorption was stable. Our study suggests that HA can be added to ordinary dentifrice to obtain dentifrice that has both relieving dentin hypersensitivity benefits and also helps to control environmental pollution.