57 research outputs found
Discrete surface solitons in semi-infinite binary waveguide arrays
We analyze discrete surface modes in semi-infinite binary waveguide arrays,
which can support simultaneously two types of discrete solitons. We demonstrate
that the analysis of linear surface states in such arrays provides important
information about the existence of nonlinear surface modes and their
properties. We find numerically the families of both discrete surface solitons
and nonlinear Tamm (gap) states and study their stability properties.Comment: 3 pages, 4 figures, submitted to Opt. Let
Fano resonance in two-dimensional optical waveguide arrays with a bi-modal defect
We study the two-dimensional extension of the Fano-Anderson model on the
basis of a two-dimensional optical waveguide array with a bi-modal defect. We
demonstrate numerically the persistence of the Fano resonance in wavepacket
scattering process by the defect. An analytical approximation is derived for
the total scattered light power
Soliton control in modulated optically-induced photonic lattices
We discuss soliton control in reconfigurable optically-induced photonic
lattices created by three interfering beams. We reveal novel dynamical regimes
for strongly localized solitons, including binary switching and soliton
revivals through resonant wave mixing.Comment: 7 pages, 5 figures. Content modifie
Demonstration of all-optical beam steering in modulated photonic lattices
We demonstrate experimentally all-optical beam steering in modulated photonic
lattices induced optically by three beam interference in a biased
photorefractive crystal. We identify and characterize the key physical
parameters governing the beam steering, and show that the spatial resolution
can be enhanced by the additional effect of nonlinear beam self-localization.Comment: 3 pages, 3 figure
Nonlinear optics and light localization in periodic photonic lattices
We review the recent developments in the field of photonic lattices
emphasizing their unique properties for controlling linear and nonlinear
propagation of light. We draw some important links between optical lattices and
photonic crystals pointing towards practical applications in optical
communications and computing, beam shaping, and bio-sensing.Comment: to appear in Journal of Nonlinear Optical Physics & Materials (JNOPM
Additional file 1: of BioWardrobe: an integrated platform for analysis of epigenomics and transcriptomics data
The following additional data are available with the online version of this paper. Additional data file 1 contains supplementary figures S1–S5, which illustrate BioWardrobe pipelines and interface and provide examples of quality control measures implemented in BioWardrobe. (PDF 3736 kb
Functional characterization of human T cell hyporesponsiveness induced by CTLA4-Ig.
During activation, T cells integrate multiple signals from APCs and cytokine milieu. The blockade of these signals can have clinical benefits as exemplified by CTLA4-Ig, which blocks interaction of B7 co-stimulatory molecules on APCs with CD28 on T cells. Variants of CTLA4-Ig, abatacept and belatacept are FDA approved as immunosuppressive agents in arthritis and transplantation, yet murine studies suggested that CTLA4-Ig could be beneficial in a number of other diseases. However, detailed analysis of human CD4 cell hyporesponsivness induced by CTLA4-Ig has not been performed. Herein, we established a model to study the effect of CTLA4-Ig on the activation of human naïve T cells in a human mixed lymphocytes system. Comparison of human CD4 cells activated in the presence or absence of CTLA4-Ig showed that co-stimulation blockade during TCR activation does not affect NFAT signaling but results in decreased activation of NF-κB and AP-1 transcription factors followed by a profound decrease in proliferation and cytokine production. The resulting T cells become hyporesponsive to secondary activation and, although capable of receiving TCR signals, fail to proliferate or produce cytokines, demonstrating properties of anergic cells. However, unlike some models of T cell anergy, these cells did not possess increased levels of the TCR signaling inhibitor CBLB. Rather, the CTLA4-Ig-induced hyporesponsiveness was associated with an elevated level of p27kip1 cyclin-dependent kinase inhibitor
Gated electron transfer reactions of truncated hemoglobin from Bacillus subtilis differently orientated on SAM-modified electrodes
Electron transfer (ET) reactions of truncated hemoglobin from Bacillus subtilis (trHb-Bs) are suggested to be implicated in biological redox signalling and actuating processes that may be used in artificial environment-sensing bioelectronic devices. Here, kinetics of ET in trHb-Bs covalently attached via its surface amino acid residues either to COOH- or NH2-terminated (CH2)(2-16) alkanethiol SAM assembled on gold are shown to depend on the alkanethiol length and functionalization, not being limited by electron tunnelling through the SAMs but gated by ET preceding reactions due to conformational changes in the heme active site/at the interface. ET gating was sensitive to the properties of SAMs that trHb-Bs interacted with. The ET rate constant k(s) for a 1e(-)/H+ reaction between the SAM-modified electrode and heme of trHb-Bs was 789 and 110 s(-1) after extrapolation to a zero length SAM, while the formal redox potential shifted 142 and 31 mV, for NH2- and COOH-terminated SAMs, respectively. Such domain-specific sensitivity and responsivity of redox reactions in trHb-Bs may be of immediate biological relevance and suggest the existence of bioelectronic regulative mechanisms of ET proceeding in vivo at the protein-protein charged interfaces that modulate the protein reactivity in biological redox signalling and actuating events
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