Cardiac multiscale bioimaging: from nano- through micro- to mesoscales.

Cardiac multiscale bioimaging is an emerging field that aims to provide a comprehensive understanding of the heart and its functions at various levels, from the molecular to the entire organ. It combines both physiologically and clinically relevant dimensions: from nano- and micrometer resolution imaging based on vibrational spectroscopy and high-resolution microscopy to assess molecular processes in cardiac cells and myocardial tissue, to mesoscale structural investigations to improve the understanding of cardiac (patho)physiology. Tailored super-resolution deep microscopy with advanced proteomic methods and hands-on experience are thus strategically combined to improve the quality of cardiovascular research and support future medical decision-making by gaining additional biomolecular information for translational and diagnostic applications

Using optical resonances to control heat generation and propagation in silicon nanostructures

Here we propose a new computational approach to light-to-matter interactions in silicon nanopillars, which simulates heat generation and propagation dynamics occurring in continuous wave laser processing over a wide temporal range (from 1 fs to about 25 hours). We show that visible light can be exploited to selectively crystallize internal region of the pillars, which is not possible by conventional treatments. A detailed study on lattice crystallization and reconstruction dynamics reveals that local heating drives the formation of secondary antennas embedded into the pillars, highlighting the importance of taking into account the spatial and temporal evolution of the optical properties of the material under irradiation. This approach can be easily extended to many types of nanostructured materials and interfaces, offering a unique computational tool for many applications involving optothermal processes.Comment: 21 pages, 4 figure

Development of Multiscale Spectro-microscopic Imaging System and Its Applications

A novel multi-modality spectro-microscopic system that combines far-field interferometry based optical microscopy imaging techniques (differential interference contrast microscopy and cross-polarized light microscopy), total internal reflection microscopy (total internal reflection fluorescence and scattering microscopy) and confocal spectroscopy (Raman spectroscopy and photoluminescence spectroscopy) is developed. Home-built post treatment stages (thermal annealing stage and solvent annealing stage) are integrated into the system to realize in situ measurements. Departing from conventional characterization methods in materials science mostly focused on structures on one length scale, the in situ multi-modality characterization system aims to uncover the structural information from the molecular level to the mesoscale. Applications of the system on the characterization of photoactive layers of bulk heterojunction solar cell, two-dimensional materials, gold nanoparticles, fabricated gold nanoparticle arrays and cells samples are shown in this dissertation

Assessment of shifted excitation Raman difference spectroscopy in highly fluorescent biological samples

Shifted excitation Raman difference spectroscopy (SERDS) can be used as an instrumental baseline correction technique to retrieve Raman bands in highly fluorescent samples. Genipin (GE) cross-linked equine pericardium (EP) was used as a model system since a blue pigment is formed upon cross-linking, which results in a strong fluorescent background in the Raman spectra. EP was cross-linked with 0.25% GE solution for 0.5 h, 2 h, 4 h, 6 h, 12 h, and 24 h, and compared with corresponding untreated EP. Raman spectra were collected with three different excitation wavelengths. For the assessment of the SERDS technique, the preprocessed SERDS spectra of two excitation wavelengths (784 nm-786 nm) were compared with the mathematical baseline-corrected Raman spectra at 785 nm excitation using extended multiplicative signal correction, rubberband, the sensitive nonlinear iterative peak and polynomial fitting algorithms. Whereas each baseline correction gave poor quality spectra beyond 6 h GE crosslinking with wave-like artefacts, the SERDS technique resulted in difference spectra, that gave superior reconstructed spectra with clear collagen and resonance enhanced GE pigment bands with lower standard deviation. Key for this progress was an advanced difference optimization approach that is described here. Furthermore, the results of the SERDS technique were independent of the intensity calibration because the system transfer response was compensated by calculating the difference spectrum. We conclude that this SERDS strategy can be transferred to Raman studies on biological and non-biological samples with a strong fluorescence background at 785 nm and also shorter excitation wavelengths which benefit from more intense scattering intensities and higher quantum efficiencies of CCD detectors. This journal i

Light-sheet microscopy: a tutorial

This paper is intended to give a comprehensive review of light-sheet (LS) microscopy from an optics perspective. As such, emphasis is placed on the advantages that LS microscope configurations present, given the degree of freedom gained by uncoupling the excitation and detection arms. The new imaging properties are first highlighted in terms of optical parameters and how these have enabled several biomedical applications. Then, the basics are presented for understanding how a LS microscope works. This is followed by a presentation of a tutorial for LS microscope designs, each working at different resolutions and for different applications. Then, based on a numerical Fourier analysis and given the multiple possibilities for generating the LS in the microscope (using Gaussian, Bessel, and Airy beams in the linear and nonlinear regimes), a systematic comparison of their optical performance is presented. Finally, based on advances in optics and photonics, the novel optical implementations possible in a LS microscope are highlighted.Peer ReviewedPostprint (published version

Light Microscopy: An ongoing contemporary revolution

Optical microscopy is one of the oldest scientific instruments that is still used in forefront research. Ernst Abbe's nineteenth century formulation of the resolution limit in microscopy let generations of scientists believe that optical studies of individual molecules and resolving sub-wavelength structures were not feasible. The Nobel Prize in 2014 for super-resolution fluorescence microscopy marks a clear recognition that the old beliefs have to be revisited. In this article, we present a critical overview of various recent developments in optical microscopy. In addition to the popular super-resolution fluorescence methods, we discuss the prospects of various other techniques and imaging contrasts and consider some of the fundamental and practical challenges that lie ahead.Comment: 37 pages, 13 figure

Correlated Multimodal Imaging in Life Sciences:Expanding the Biomedical Horizon

International audienceThe frontiers of bioimaging are currently being pushed toward the integration and correlation of several modalities to tackle biomedical research questions holistically and across multiple scales. Correlated Multimodal Imaging (CMI) gathers information about exactly the same specimen with two or more complementary modalities that-in combination-create a composite and complementary view of the sample (including insights into structure, function, dynamics and molecular composition). CMI allows to describe biomedical processes within their overall spatio-temporal context and gain a mechanistic understanding of cells, tissues, diseases or organisms by untangling their molecular mechanisms within their native environment. The two best-established CMI implementations for small animals and model organisms are hardware-fused platforms in preclinical imaging (Hybrid Imaging) and Correlated Light and Electron Microscopy (CLEM) in biological imaging. Although the merits of Preclinical Hybrid Imaging (PHI) and CLEM are well-established, both approaches would benefit from standardization of protocols, ontologies and data handling, and the development of optimized and advanced implementations. Specifically, CMI pipelines that aim at bridging preclinical and biological imaging beyond CLEM and PHI are rare but bear great potential to substantially advance both bioimaging and biomedical research. CMI faces three mai

Making microscopy count: quantitative light microscopy of dynamic processes in living plants

First published: April 2016This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Cell theory has officially reached 350 years of age as the first use of the word ‘cell’ in a biological context can be traced to a description of plant material by Robert Hooke in his historic publication “Micrographia: or some physiological definitions of minute bodies”. The 2015 Royal Microscopical Society Botanical Microscopy meeting was a celebration of the streams of investigation initiated by Hooke to understand at the sub-cellular scale how plant cell function and form arises. Much of the work presented, and Honorary Fellowships awarded, reflected the advanced application of bioimaging informatics to extract quantitative data from micrographs that reveal dynamic molecular processes driving cell growth and physiology. The field has progressed from collecting many pixels in multiple modes to associating these measurements with objects or features that are meaningful biologically. The additional complexity involves object identification that draws on a different type of expertise from computer science and statistics that is often impenetrable to biologists. There are many useful tools and approaches being developed, but we now need more inter-disciplinary exchange to use them effectively. In this review we show how this quiet revolution has provided tools available to any personal computer user. We also discuss the oft-neglected issue of quantifying algorithm robustness and the exciting possibilities offered through the integration of physiological information generated by biosensors with object detection and tracking

Recent Developments in Atomic Force Microscopy and Raman Spectroscopy for Materials Characterization

This book contains chapters that describe advanced atomic force microscopy (AFM) modes and Raman spectroscopy. It also provides an in-depth understanding of advanced AFM modes and Raman spectroscopy for characterizing various materials. This volume is a useful resource for a wide range of readers, including scientists, engineers, graduate students, postdoctoral fellows, and scientific professionals working in specialized fields such as AFM, photovoltaics, 2D materials, carbon nanotubes, nanomaterials, and Raman spectroscopy

In situ studies of catalytic processes by Near Ambient X-ray Photoelectron Spectroscopy

A a portada logotip del Sincrotò "Alba"(English) Labels misplacement in the bottles are currently causing problems in wine cellar's labelling lines. According to data provided by Codorníu and Torres cellars, 1 % of the bottles present this issue. Once the wine or cava have been bottled, the bottles pass through the labeling station and the scanner separates the correctly labeled bottles from those with imperfections. When a considerable number of bottles are involved, the wine is emptied and rebottled, while the labeled bottle is discarded. However, if few bottles are mislabeled, a worker manually removes the labels with a scraper and retums the bottles to the labeling line. Of course, this is a problem. In this thesis, a system has been developed consisting of a pressure-sensitive adhesive anda detaching station that allows the adhesive to be deactivated for easy removal of misplaced labels. The adhesive had to meet the current market requirements and to be easily peeled off easily in the detaching station to leave the bottle completely clean to it can be relabelled without being taken out of the labelling lines. As bottles are full when they pass through the detaching station, a technology that could quickly remove the labels from the bottles at 25ºC was required to avoid affecting the quality of the product. lt was designed to include a cleaning solution bath, a thermostatic, and a mechanical agitator. Several chemical components with different weight ratios were tested for the cleaning solution formulation to determine the most effective solution. The design of the adhesive was sub-divided into 5 parts. First, the influence of the soft monomers: n-butyl acrylate and 2- ethylhexyl acrylate influence was studied via semi-batch emulsion polymerization taking as a starting point a formulation recipe composed of n-butyl acrylate and acrylic acid. In the second part, the influence of including a hard monomer, such as acrylonitrile, was studied. In both studies it was observed that the adhesives showed poor water resistance. For it, in the third part, different polymerizable surfactants were studied as stabilizer of the emulsion and were compared with the conventional surfactant used in the base formulation. The use a polymerizable surfactant clear1y increased the water resistance of the adhesives. Although the incorporation of 2-ethylhexyl acrylate showed better adhesive performance, the acrylonitrile showed better results in the detaching bath. For it, it was decided to continue the experiments introducing in the formulation the weight ratio of acrylonitrile that showed the best balance between the adhesive properties and its performance in the detaching bath and the polymerizable surfactant that showed the highest water resistance. In the fourth part, the optimization of the adhesive properties balance was carried out by the study of the influence of acrylic acid as functional monomer and the tert-dodecyl mercaptan as chain transfer agent. Clearly, the acrylic acid improved all adhesive properties. However, the maximum amount of acrylic acid testad only improved the shear resistance since with the gel content increase, the peel resistance and tack properties deceased. On the other hand, the chain transfer agent only improved the peel resistance and tack. Therefore, it was not possible to achieve a good performance among the three adhesive properties. Finally, the influence of adhesiva preparation process was investigated. In this case an improvement in the balance of adhesive properties was observed. Several of the pressure-sensitive adhesives carne close to current market requirements, as well as showing excellent results in the detaching station.(Català) Els nanomaterials han rebut malta atracció com a catalitzadors no només perla seva elevada relació superfície-volum, sinó també perla capacitat de sintetitzar-los en diferents dimensions i formes, les quals poden influir en els processos catalítics tot exposant plans cristal·logràfics específics. Degut al caràcter superficial de la catàlisi, l'ús de tècniques sensibles a la superfície és clau, però la investigació de sistemes catalítics s'ha de fer en les condicions més realistes possibles (en condicions de reacció) per poder identificar i comprendre el comportament de les espècies actives en condicions de treball. Aquest tipus d’estudis són possibles mitjançant l’espectroscòpia fotoelectrònica de raigs-X en pressions properes a l’ambient (NAP-XPS). En aquest context, les principals línies d'investigació d'aquesta tesi, dividida entres capítols, s'han centrat en el disseny, síntesi i caracterització fisicoquímica de catalitzadors basats en cèria i deis seus centres actius, especialment mitjançant espectroscòpia fotoelectrònica de raigs-X en condicions “operando”, en dues reaccions especifiques: la oxidació del sutge i la oxidació del CO. La primera part esta dedicada a la síntesi de múltiples catalitzadors diòxid de ceri amb diferent nanoforma (cubs, bastonets, octaedres i poliedres, així com cubs i bastonets microestructurats amb plans {111}) per estudiar la influència deis plans exposats en la seva activitat catalítica per la reacció d’oxidació del sutge. S'ha avaluat la seva activitat catalítica per l'oxidació del sutge, i els nanocubs i bastonets de cèria (amb domini de cares {100} i {110}) mostren la millar activitat específica d'oxidació del sutge. Les mesures NAP-XPS han demostrat que les cares {100} i {11O} presenten la quantitat més elevada de Celll i de vacants d'oxigen durant el seu escalfament en atmosfera d'argó, i que la presència de sutge ha promogut altament la formació de Celll, confirmat també mitjançant ex-situ i “operando” Raman. La segona partes focalitza en l'estudi de la reacció d'oxidació de CO sobre un catalitzador policristal·lí de Pd/CeO2 per investigar la interacció entre el pal·ladi i el suport de céria i determinar la seva morfologia i la composició química i estructura electrònica deis diferents elements en la superfície de la mostra. S'ha preparat i caracteritzat fisicoquímicament un catalitzador convencional en pols (Pd/CeO2) abans d'estudiar la seva activitat per l'oxidació de CO amb NAP-XPS. Les mesures “operando” han permès la identificació de dues especies de Pd diferents en condicions d'oxidació de CO, essent PdxCe1-xO2--0 la fase activa. Aquesta part també inclou una anàlisi no destructiu del perfil de profunditat tot utilitzant energies d'excitació de sincrotró variables, dut a terme per esclarir la ubicació i el paper d'aquestes espècies de pal·ladi en la reacció d'estudi. La tercera i última partes basa en el disseny i preparació de catalitzadors inversos cèria/Pd mitjançant la deposició de capa atòmica (ALD) per investigar la reacció d'oxidació de CO en condicions “operando”. S'ha preparat i caracteritzat morfològicament un sistema model Pd/CeO2/Si i diversos sistemes inversos CeO2/Pd per investigar el rol de les diferents interfícies formades en l'activitat de la reacció esmentada. La optimització del disseny del sistema invers cèria/Pd ha comportat un estudi de la influència de la temperatura i del nombre de cicles de deposició sobre l'estructura i l'activitat d'aquests sistemes, i s'ha establert una relació entre la rugositat superficial deis sistemes i el nombre de cicles de deposició. També s'ha fet un seguiment de l'efecte de la temperatura sobre la uniformitat i continuïtat de les capes fines deis sistemes. Les mesures de NAP-XPS han permès concloure que 100 cicles d'ALD són el valor òptim que permet estudiar les fases de Ce i Pd deis sistemes, i que la presència de la fase activa PdxCe1-xOPostprint (published version