Simultaneous co-localized super-resolution fluorescence microscopy and atomic force microscopy: combined SIM and AFM platform for the life sciences

Correlating data from different microscopy techniques holds the potential to discover new facets of signaling events in cellular biology. Here we report for the first time a hardware set-up capable of achieving simultaneous co-localized imaging of spatially correlated far-field super-resolution fluorescence microscopy and atomic force microscopy, a feat only obtained until now by fluorescence microscopy set-ups with spatial resolution restricted by the Abbe diffraction limit. We detail system integration and demonstrate system performance using sub-resolution fluorescent beads and applied to a test sample consisting of human bone osteosarcoma epithelial cells, with plasma membrane transporter 1 (MCT1) tagged with an enhanced green fluorescent protein (EGFP) at the N-terminal.Ana I. Gomez Varela wishes to acknowledge support from the Xunta de Galicia, Conselleria de Cultura, Educacion e Ordenacion Universitaria e da Conselleria de Economia, Emprego e Industria (Programa de axudas de apoio a etapa de formacion posdoutoral 2017). Adelaide Miranda and Pieter De Beule acknowledge financial support from Norte's Regional Operational Programme 2014-2020-Norte2020 (NORTE-01-0145-FEDER-000019). Sandra Paiva and Rosana Alves thank Fulbright Commission Portugal and Luso-American Development Foundation (FLAD) for their financial support to perform research work at UC Berkeley, California, USA. We thank the U.S. Embassy in Portugal for supporting David Drubin's visit to Portugal. We thank Ann Fisher of the UC Berkeley Cell Culture Facility for help with cell culture. We thank Dr. Kartoosh Heydari of the Cancer Research Lab Flow Cytometry Core Facility of UC Berkeley. Rosana Alves and Claudia Barata-Antunes are recipients of PhD fellowships from the Portuguese Foundation for Science and Technology (PD/BD/113813/2015 and PD/BD/135208/2017, respectively). The authors want to thank Nikon and Izasa Scientific for their support to the experiment by providing a N SIM-E microscope set-up on loan. We also gratefully acknowledge Dr. Kees van der Oord from Nikon Instruments Europe B.V. for his assistance with the SIM microscope as well as Paulo Madureira and Carlos Pitaes from IZASA Portugal and Jordi Recasens from IZASA Spain for their assistance with the integration of the SIM and AFM microscopes. Finally, we want to thank Benjamin Holmes for fruitful discussions and relentless support

Global exponential stability for a class of impulsive BAM neural networks with distributed delays

In this paper, the exponential stability is investigated for a class of BAM neural networks with distributed delays and nonlinear impulsive operators. By using Lyapunov functions and applying the Razumikhin technique, delay–independent sufficient conditions ensuring the global exponential stability of equilibrium points are derived. These results can easily be utilized to design and verify globally stable networks. An illustrative example is given to demonstrate the effectiveness of the obtained results

Nonequilibrium processes in meta-stable media

Meta-stable systems are those staying in the local equilibrium state: being slightly deviated from it they return to the equilibrium, but in case deviation surpasses a critical value those systems fall down to another equilibrium state. Chemically reacting gaseous mixture provides a typical example of a meta-stable system. The paper is aimed at numerical and experimental investigation of detonation initiation in hydrogen-air mixtures due to focusing of a shock wave reflected inside a wedge. Both numerical and experimental investigations were conducted. Comparison of numerical and experimental results made it possible to validate the developed 3D transient mathematical model of chemically reacting gas mixture flows incorporating hydrogen-air mixtures. Kinetic schemes and turbulence models were improved based on comparison of numerical and experimental results. Several different flow scenarios manifest in the reflection of shock waves all being dependent on the incident shock wave intensity: reflection of the shock wave with lagging behind the combustion zone, formation of a detonation wave in reflection and focusing, and intermediate transient regimes