Control of Oscillation Patterns in a Symmetric Coupled Biological Oscillator System

A chain of three-oscillator system was constructed with living biological oscillators of phasmodial slime mold, Physarum polycehalum and the oscillation patterns were analyzed by the symmetric Hopf bifurcation theory using group theory. Multi-stability of oscillation patterns was observed, even when the coupling strength was fixed. This suggests that the coupling strength is not an effective parameter to obtain a desired oscillation pattern among the multiple patterns. Here we propose a method to control oscillation patterns using resonance to external stimulus and demonstrate pattern switching induced by frequency resonance given to only one of oscillators in the system

Plasmon-molecule remote coupling via column-structured silica layer for enhancing biophotonic analysis

We demonstrated remote plasmonic enhancement (RPE) by a dense random array of Ag nanoislands (AgNIs) that were partially gold-alloyed and attached with column-structured silica (CSS) overlayer of more than 100 nm in thickness. The physical and chemical protection of the CSS layer could lead to reducing the mutual impact between analyte molecules and metal nanostructures. RPE plate was realized just by sputtering and chemical immersion processes, resulting in high productivity. We found a significant enhancement on the order of 10$^7$-fold for Raman scattering and 10$^2$-fold for fluorescence by RPE even without the proximity of metal nanostructures and analyte molecules. We confirmed the feasibility of RPE for biophotonic analysis. RPE worked for dye molecules in cells cultured on the CSS layer, enabling the enhanced fluorescence biosensing of intracellular signaling dynamics in HeLa cells. RPE also worked for biological tissues, enhancing Raman histological imaging of esophagus tissues with esophageal adventitia of a Wistar rat attached atop the CSS layer. We also investigated the wavelength dependency of RPE on the on- or off-resonant with the dye molecular transition dipoles with various molecular concentrations. The results suggested that the RPE occurred by remote resonant coupling between the localized surface plasmon of AgNIs and the molecular transition dipole of the analyte via the CSS structure. The RPE plate affords practical advantages for potential biophotonic analyses such as high productivity and biocompatibility. We thus anticipate that RPE will advance to versatile analytical tools in chemistry, biology, and medicine.Comment: 34 pages, 11 figures, 1 tabl

Characterization of Leukocyte Mono-immunoglobulin-like Receptor 7 (LMIR7)/CLM-3 as an Activating Receptor: ITS SIMILARITIES TO AND DIFFERENCES FROM LMIR4/CLM-5*

Here we characterize leukocyte mono-Ig-like receptor 7 (LMIR7)/CLM-3 and compare it with an activating receptor, LMIR4/CLM-5, that is a counterpart of an inhibitory receptor LMIR3/CLM-1. LMIR7 shares high homology with LMIR4 in the amino acid sequences of its Ig-like and transmembrane domains. Flow cytometric analysis demonstrated that LMIR4 was predominantly expressed in neutrophils, whereas LMIR7 was highly expressed in mast cells and monocytes/macrophages. Importantly, LMIR7 engagement induced cytokine production in bone marrow-derived mast cells (BMMCs). Although FcRγ deficiency did not affect surface expression levels of LMIR7, it abolished LMIR7-mediated activation of BMMCs. Consistently we found significant interaction of LMIR7-FcRγ, albeit with lower affinity compared with that of LMIR4-FcRγ. Our results showed that LMIR7 transmits an activating signal through interaction with FcRγ. In addition, like LMIR4, LMIR7 synergizes with TLR4 in signaling. Analysis of several chimera receptors composed of LMIR4 and LMIR7 revealed these findings: 1) the transmembrane of LMIR7 with no charged residues maintained its surface expression at high levels in the absence of FcRγ; 2) the extracellular juxtamembrane region of LMIR7 had a negative effect on its surface expression levels; and 3) the strong interaction of LMIR4 with FcRγ depended on the extracellular juxtamembrane region as well as the transmembrane domain of LMIR4. Thus, LMIR7 shares similarities with LMIR4, although they are differentially regulated in their distribution, expression, and function