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Objective: Fibroblast‐like synoviocytes (FLSs) contribute to inflammation and joint damage in rheumatoid arthritis (RA). However, the regulatory mechanisms of FLSs in relapse and remission of RA remain unknown. Identifying FLS heterogeneity and their underlying pathogenic roles may lead to discovering novel disease‐modifying antirheumatic drugs. Methods: Combining single‐cell RNA sequencing (scRNA‐seq) and spatial transcriptomics, we sequenced six matched synovial tissue samples from three patients with relapse RA and three patients in remission. We analyzed the differences in the transcriptomes of the FLS subsets between the relapse and remitted phases. We validated several key signaling pathways using quantitative real‐time PCR (qPCR) and multiplex immunohistochemistry (mIHC). We further targeted the critical signals in vitro and in vivo using the collagen‐induced arthritis (CIA) model in rats. Results: Lining and sublining FLS subsets were identified using scRNA‐seq. Differential analyses indicated that the fibroblast growth factor (FGF) pathway was highly activated in the lining FLSs from patients with relapse RA for which mIHC confirmed the increased expression of FGF10. Although the type I interferon pathway was also activated in the lining FLSs, in vitro stimulation experiment suggested that it was independent of the FGF10 pathway. FGF10 knockdown by small interfering RNA in FLSs significantly reduced the expression of receptor activator of NF‐κB ligand. Moreover, recombinant FGF10 protein enhanced bone erosion in the primary human‐derived pannus cell culture, whereas the FGF receptor (FGFR) 1 inhibitor attenuated this process. Finally, administering an FGFR1 inhibitor displayed a therapeutic effect in a CIA rat model. Conclusion: The FGF pathway is a critical signaling pathway in relapse RA. Targeted tissue‐specific inhibition of FGF10/FGFR1 may provide new opportunities to treat patients with relapse RA. [ABSTRACT FROM AUTHOR]

Self assembled monolayer (SAM) films of carboxymethyl chitosan (CM-CHI) were prepared by immersing mica in CM-CHI aqueous solution at pH = 1.7. The obtained films were further rinsed in baths of water at different pH. The pH induced morphological change of carboximethyl chitosan SAM films was investigated by atomic force microscope using tapping mode. The results showed that the morphology of the films was remarkably affected by the pH of rinse bath. Three obvious morphological changes were discussed and explained by the competition between electrostatic interaction and hydrogen bond. We draw attention to the 'Crater' structures in the films and find that the formation and evolution of 'Crater' structures have a close relationship with the pH of rinse bath. The formation mechanism of the other two special structures was also discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

Synthetic aperture sequential beamforming (SASB) is a two‐stage delay‐and‐sum beamforming procedure, which can be applied to B‐mode imaging with an implementation of low complexity compared to the traditional synthetic transmit aperture imaging. A new SASB imaging scheme in order to compensate the effects of axial motion is proposed. The velocity and direction of the motion can be evaluated by cross‐correlation between specific beams according to adjacent focus of the SASB. The performance assessment, conducted by using simulated data, reveals that the proposed method can correct the positions of tissue motion without extra firings. [ABSTRACT FROM AUTHOR]