800nm fiber Bragg Grating sensing interrogation system using TFBG and CCD array

An 800nm band fiber Bragg grating sensing interrogation system using TFBG as the core wavelength division component is presented. A charge coupled device (CCD) linear array is put on the focal plane of the lens to detect the light. TFBG is used to tap light out of the fiber core to fiber cladding. The sensing wavelength is 795 to 830nm, with accuracy of 20pm and scan speed 100Hz. Using FBG sensor, we achieve the temperature sensitivity as 1.8°C and strain sensitivity as 18με

Salmonella Infection Causes Hyperglycemia for Decreased GLP-1 Content by Enteroendocrine L Cells Pyroptosis in Pigs

Inflammatory responses have been shown to induce hyperglycemia, yet the underlying mechanism is still largely unclear. GLP-1 is an important intestinal hormone for regulating glucose homeostasis; however, few studies have investigated the influence of digestive tract Salmonella infection on enteroendocrine L cell secretions. In this study, we established a model of Salmonella-infected piglets by oral gavage in order to analyze the effects of Salmonella infection on enteroendocrine L cell function. Furthermore, in vitro lipopolysaccharide (LPS) was administered to STC-1 cells to clarify its direct effect on GLP-1 secretion. The results showed that significantly increased blood glucose in the group of Salmonella-infected piglets was observed, and Salmonella infection decreased blood GLP-1 content. Then, ileal epithelium damage was observed by histological detection, and this was further verified by TUNEL staining. We identified activation of TLR signaling demonstrating up-regulated expressions of TLR4 and nuclear factor-kappa B (NF-ΚB). Furthermore, it was shown that Salmonella induced pyroptosis of enteroendocrine L cells and enhanced the secretion of IL-1β through augmenting gene and protein expressions of NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a carboxyl-terminal CARD (ASC), Caspase 1, and gasdermin D (GSDMD). Meanwhile, in vitro LPS treatment induced the pyroptosis of STC-1 cells and reduced the secretion of GLP-1. Altogether, the results demonstrated that Salmonella infection can reduce secretion of GLP-1 by inducing pyroptosis of intestinal L cells, which may eventually result in hyperglycemia. The results provided evidence for the cause of hyperglycemia induced by inflammation and shed new light on glucose homeostasis regulation