A5077645019- Advanced Fluorescence Microscopy Techniques
- Bacteriophages and microbial interactions
- Advanced biosensing and bioanalysis techniques
- DNA and Nucleic Acid Chemistry
- Lipid Membrane Structure and Behavior
- Immunotherapy and Immune Responses
- Cell Image Analysis Techniques
- Fractional Differential Equations Solutions
- Diffusion and Search Dynamics
- Bacterial Genetics and Biotechnology
- Cell Adhesion Molecules Research
- stochastic dynamics and bifurcation
- Advanced Electron Microscopy Techniques and Applications
- Liver physiology and pathology
- Spectroscopy and Quantum Chemical Studies
- RNA Interference and Gene Delivery
- Plasmonic and Surface Plasmon Research
- Force Microscopy Techniques and Applications
- Caveolin-1 and cellular processes
- Glycosylation and Glycoproteins Research
- Near-Field Optical Microscopy
- Gene Regulatory Network Analysis
- Nanopore and Nanochannel Transport Studies
- Gaussian Processes and Bayesian Inference
- Molecular spectroscopy and chirality
Universitat de Vic - Universitat Central de Catalunya
2017-2024
Institute of Photonic Sciences
2013-2023
Barcelona Institute for Science and Technology
2023
Max Planck Institute of Molecular Cell Biology and Genetics
2023
Queen Mary University of London
2023
William Harvey Research Institute
2023
Quantitative BioSciences
2019
University of Naples Federico II
2016
University of Campania "Luigi Vanvitelli"
2016
Emory University
2007-2014
We demonstrate experimentally an optical process in which the spin angular momentum carried by a circularly polarized light beam is converted into orbital momentum, leading to generation of helical modes with wave-front helicity controlled input polarization. This phenomenon requires interaction matter that both optically inhomogeneous and anisotropic. The underlying physics also associated so-called Pancharatnam-Berry geometrical phases involved any transformation
Nonergodicity observed in single-particle tracking experiments is usually modeled by transient trapping rather than spatial disorder. We introduce models of a particle diffusing medium consisting regions with random sizes and diffusivities. The never trapped, but performs continuous Brownian motion the local diffusion constant. Under simple assumptions on distribution diffusivities, we find that mean squared displacement displays subdiffusion due to non-ergodicity for both annealed quenched...
Deviations from Brownian motion leading to anomalous diffusion are ubiquitously found in transport dynamics, playing a crucial role phenomena quantum physics life sciences. The detection and characterization of the measurement an individual trajectory challenging tasks, which traditionally rely on calculating mean squared displacement trajectory. However, this approach breaks down for cases important practical interest, e.g., short or noisy trajectories, ensembles heterogeneous non-ergodic...
We report the realization of a Pancharatnam-Berry phase optical element [Z. Bomzon, G. Biener, V. Kleiner, and E. Hasman, Opt. Lett. 27, 1141 (2002)], for wave front shaping working in visible spectral domain, based on patterned liquid crystal technology. This device generates helical modes light with possibility electro-optically switching between opposite helicities by controlling handedness input circular polarization. By cascading this approach, fast among multiple can be achieved,...
Fundamental biological processes, including the capture of pathogens by membrane receptors, are regulated molecular transport. Scientists show that receptor functioning is linked to nonergodic dynamics, which refers difference between properties a particle and an ensemble particles.
Abstract In order to study transport in complex environments, it is extremely important determine the physical mechanism underlying diffusion and precisely characterize its nature parameters. Often, this task strongly impacted by data consisting of trajectories with short length (either due brief recordings or previous trajectory segmentation) limited localization precision. paper, we propose a machine learning method based on random forest architecture, which able associate single high...
Abstract The characterization of dynamical processes in living systems provides important clues for their mechanistic interpretation and link to biological functions. Owing recent advances microscopy techniques, it is now possible routinely record the motion cells, organelles individual molecules at multiple spatiotemporal scales physiological conditions. However, automated analysis dynamics occurring crowded complex environments still lags behind acquisition microscopic image sequences....
Lateral segregation of cell membranes is accepted as a primary mechanism for cells to regulate diversity cellular functions. In this context, lipid rafts have been conceptualized organizing principle biological where underlying cholesterol-mediated selective connectivity must exist even at the resting state. However, such level nanoscale compositional has challenging prove. Here we used single-molecule near-field scanning optical microscopy visualize nanolandscape raft ganglioside GM1 after...
MADS domain transcription factors are key regulators of eukaryotic development. In plants, the homeotic MIKC that regulate floral organ identity have been studied in great detail. Based on genetic and protein–protein interaction studies, a quartet model was proposed describes how these proteins assemble into higher order complexes to their target genes. However, despite attractiveness this its general acceptance literature, solid vivo proof has never provided. To gain deeper insight...
Glycan-protein interactions are emerging as important modulators of membrane protein organization and dynamics, regulating multiple cellular functions. In particular, it has been postulated that glycan-mediated regulate surface residence time glycoproteins endocytosis. How this precisely occurs is poorly understood. Here we applied single-molecule-based approaches to directly visualize the impact glycan-based on spatiotemporal interaction with clathrin glycosylated pathogen recognition...
Abstract Sphingolipids are essential constituents of the plasma membrane (PM) and play an important role in signal transduction by modulating clustering dynamics receptors. Changes lipid composition therefore likely to influence receptor organisation function, but how this precisely occurs is difficult address given intricacy PM lipid-network. Here, we combined biochemical assays single molecule dynamic approaches demonstrate that local environment regulates adhesion integrin receptors...
We present a modeling approach for diffusion in complex medium characterized by random length scale. The resulting stochastic process shows subdiffusion with behavior qualitative agreement single-particle tracking experiments living cells, such as ergodicity breaking, $p$ variation, and aging. In particular, this recapitulates characteristic features previously described part the fractional Brownian motion continuous-time walk. Moreover, proper distribution of scale, single parameter...
Assembly and disassembly of adhesion structures such as focal adhesions (FAs) podosomes regulate cell differentiation. On antigen-presenting dendritic cells (DCs), acquisition a migratory immunostimulatory phenotype depends on podosome dissolution by prostaglandin E(2) (PGE(2)). Whereas the effects physico-chemical topographical cues have been extensively studied FAs, little is known about how respond to these signals. Here, we show that, unlike for formation not controlled substrate...
The C-type lectin DC-SIGN expressed on dendritic cells (DCs) facilitates capture and internalization of a plethora different pathogens. Although it is known that organizes in nanoclusters at the surface DCs, molecular mechanisms responsible for this well defined nanopatterning role viral binding remain enigmatic. By combining biochemical advanced biophysical techniques, including optical superresolution single particle tracking, we demonstrate intrinsic nanoclustering strictly depends its...
Significance Low levels of λ repressor (CI) can autoenhance expression and lysogeny (quiescence) bacteriophage infection. However, additional CI mediates an autorepressive DNA loop. Supercoiling catalyzes looping in unstretched plasmids, but whether supercoiling under tension, the cI promoter within loop becomes superhelically isolated were investigated. efficiently partitioned plasmids into topological domains formed barriers to passage from one another. Furthermore, single molecules...
Optical nanoantennas can efficiently confine light into nanoscopic hotspots, enabling single-molecule detection sensitivity at biological relevant conditions. This innovative approach to breach the diffraction limit offers a versatile platform investigate dynamics of individual biomolecules in living cell membranes and their partitioning cholesterol-dependent lipid nanodomains. Here, we present optical nanoantenna arrays with accessible surface hotspots study characteristic diffusion...
Transmembrane adhesion receptors at the cell surface, such as CD44, are often equipped with modules to interact extracellular matrix (ECM) and intracellular cytoskeletal machinery. CD44 has been recently shown compartmentalize membrane into domains by acting pickets, facilitating function of signaling receptors. While spatial organization diffusion studies proteins usually conducted separately, here we combine observations using high spatio-temporal resolution imaging on living cells reveal...
The immunoglobulin-like lectin receptor CD169 (Siglec-1) mediates the capture of HIV-1 by activated dendritic cells (DCs) through binding to sialylated ligands. These interactions result in a more efficient virus as compared resting DCs, although underlying mechanisms are poorly understood. Using combination super-resolution microscopy, single-particle tracking and biochemical perturbations we studied nanoscale organization Siglec-1 on DCs its impact viral trafficking single viral-containing...
Recently, it was proposed that DNA looping by the λ repressor (CI protein) strengthens repression of lytic genes during lysogeny and simultaneously ensures efficient switching to lysis. To investigate this hypothesis, tethered particle motion experiments were performed dynamic CI-mediated single molecules containing binding sites separated 2317 bp (the wild-type distance) quantitatively analyzed. all three intact operators or with mutated o3 compared. Modeling thermodynamic data established...