Conception d'un laboratoire sur fibre pour l'analyse in vivo

International audienceThis work presents the proof of concept of the detection of optical index changes by surface plasmon resonance (SPR) thanks to optical fiber bundles. This proof of concept is the first essential step for the future design of a lab on fiber tool dedicated to molecular analysis for endoscopic diagnosis. Our approach is based on nanotextured optical fiber bundles comprising several thousands of individual optical fibers. These nanostructures were coated by a thin gold layer in order to exhibit interesting optical properties like SPR. The sensitivity of the bundle to optical index changes and the detection limit were measured in retro-reflection. We performed numerical simulations in order to enhance these performances based on an optimization of the fiber end geometry and the gold coating thickness. We finally obtained a detection limit of 10-4 refractive index unit, which is fully compatible with the detection of biological interactions involving large proteins or bacteria. </p

pKa tuning in quadrupolar-type two-photon ratiometric fluorescent membrane probes

International audienceTwo bolaamphiphilic quadrupoles built from a fluorene core conjugated with azine endgroups were designed and successfully used to stain GUV membranes. Their quadrupolar character induces both a shift of the pKa values close to the physiological pH and large two-photon absorption responses (i.e. over 1000 GM for acidic forms). As such they hold promise as ratiometric two-photon pH probes for monitoring slight variations of pH near cell membranes using two-photon excitation in the NIR regio

Challenge clusters facing LCA in environmental decision-making—what we can learn from biofuels

Purpose Bioenergy is increasingly used to help meet greenhouse gas (GHG) and renewable energy targets. However, bioenergy’s sustainability has been questioned, resulting in increasing use of life cycle assessment (LCA). Bioenergy systems are global and complex, and market forces can result in significant changes, relevant to LCA and policy. The goal of this paper is to illustrate the complexities associated with LCA, with particular focus on bioenergy and associated policy development, so that its use can more effectively inform policymakers. Methods The review is based on the results from a series of workshops focused on bioenergy life cycle assessment. Expert submissions were compiled and categorized within the first two workshops. Over 100 issues emerged. Accounting for redundancies and close similarities in the list, this reduced to around 60 challenges, many of which are deeply interrelated. Some of these issues were then explored further at a policyfacing workshop in London, UK. The authors applied a rigorous approach to categorize the challenges identified to be at the intersection of biofuels/bioenergy LCA and policy. Results and discussion The credibility of LCA is core to its use in policy. Even LCAs that comply with ISO standards and policy and regulatory instruments leave a great deal of scope for interpretation and flexibility. Within the bioenergy sector, this has led to frustration and at times a lack of obvious direction. This paper identifies the main challenge clusters: overarching issues, application and practice and value and ethical judgments. Many of these are reflective of the transition from application of LCA to assess individual products or systems to the wider approach that is becoming more common. Uncertainty in impact assessment strongly influences planning and compliance due to challenges in assigning accountability, and communicating the inherent complexity and uncertainty within bioenergy is becoming of greater importance. Conclusions The emergence of LCA in bioenergy governance is particularly significant because other sectors are likely to transition to similar governance models. LCA is being stretched to accommodate complex and broad policy-relevant questions, seeking to incorporate externalities that have major implications for long-term sustainability. As policy increasingly relies on LCA, the strains placed on the methodology are becoming both clearer and impedimentary. The implications for energy policy, and in particular bioenergy, are large

Supplementary data for the article: Habtamu, H. B.; Sentic, M.; Silvestrini, M.; De Leo, L.; Not, T.; Arbault, S.; Manojlovic, D.; Sojic, N.; Ugo, P. A Sensitive Electrochemiluminescence Immunosensor for Celiac Disease Diagnosis Based on Nanoelectrode Ensembles. Analytical Chemistry 2015, 87 (24), 12080–12087. https://doi.org/10.1021/acs.analchem.5b02801

Supporting information for: [https://doi.org/10.1021/acs.analchem.5b02801]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2014

Selective electrochemiluminescent sensing of saccharides using boronic acid-modified coreactant

We report a strategy for modulating the electrogenerated chemiluminescence (ECL) response by integrating a boronic acid to the chemical structure of coreactants. Excellent selectivity for d-glucose was achieved by tuning the linker length of a bis-boronic acid amine coreactant.</p

Supplementary data for the article: Habtamu, H. B.; Sentic, M.; Silvestrini, M.; De Leo, L.; Not, T.; Arbault, S.; Manojlovic, D.; Sojic, N.; Ugo, P. A Sensitive Electrochemiluminescence Immunosensor for Celiac Disease Diagnosis Based on Nanoelectrode Ensembles. Analytical Chemistry 2015, 87 (24), 12080–12087. https://doi.org/10.1021/acs.analchem.5b02801

Supporting information for: [https://doi.org/10.1021/acs.analchem.5b02801]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2014

3D electrogenerated chemiluminescence: from surface-confined reactions to bulk emission

Among luminescence techniques, electrogenerated chemiluminescence (ECL) provides a unique level of manipulation of the luminescent process by controlling the electrochemical trigger. Despite its attractiveness, ECL is by essence a 2D process where light emission is strictly confined to the electrode surface. To overcome this intrinsic limitation, we added a new spatial dimension to the ECL process by generating 3D ECL at the level of millions of micro-emitters dispersed in solution. Each single object is addressed remotely by bipolar electrochemistry and they generate collectively the luminescence in the bulk. Therefore, the entire volume of the solution produces light. To illustrate the generality of this concept, we extended it to a suspension of multi-walled carbon nanotubes where each one acts as an individual ECL nano-emitter. This approach enables a change of paradigm by switching from a surface-limited process to 3D electrogenerated light emission

ALIGNED D1.2:A scientific framework for the Life Cycle Assessment of bio-based products

The poster presents the deliverable D1.2 “Description of scientific methods” of the ALIGNED project (Horizon Europe), that proposes the results of the project work to derive a scientific framework for the life cycle assessment of bio-based products – to be applied in the project and more broadly to improve the environmental performance of bio-based industrial activities in multiple sectors.We reviewed, selected, and further developed and made operational best available methods for the assessment of bio-based products encompassing all the four ISO phases (from goal and scope to interpretation) – the results is a coherent framework that includes approaches, methods, and tools, that can be used consistently together and have high scientific soundness and are evidence-based, with as little normative elements as possible.In particular the framework includes: methods for generating dynamic background systems for prospective LCA of bio-based products; methods for identification of market constraints to the supply of biomass; methods for time and space-dependent carbon accounting in bio-based carbon uptake and release activities able to return mass balanced carbon inventories; methods and characterisation factors for dynamic assessment of climate change and spatially explicit assessment of biodiversity impacts; methods for uncertainty and sensitivity analysis in bio-based sectors; methods for socio-economic assessment in bio-based sectors. Additionally, methods and tools are provided for sharing and publishing life cycle inventory data, sharing them, importing in software, and enhancing reproducibility and in compliance with FAIR principles and GLAD requirements.The deliverable D1.2 consists of a series of documents such as guidelines, routines, algorithms, datasets, models, spreadsheets, calculators, codes, and notebooks - all available in open access task-specific project repositories. The presentation will describe the specific purpose and associated content of each part of the methodological framework and provide an overview and map for understanding and navigating the material associated with the deliverable and how to access and use it.<br/

In situ electrochemical monitoring of reactive oxygen and nitrogen species released by single MG63 osteosarcoma cell submitted to a mechanical stress

The oxidative stress responses of single MG63 osteosarcoma cells submitted to a brief mechanical stress have been investigated by amperometry at platinized carbon fiber electrodes for monitoring and characterizing the nature and the amounts of the various reactive oxygen (ROS) and reactive nitrogen species (RNS) released. It was thus shown that, on average, a single MG63 cell released prominent amounts of reactive nitrogen species (17 fmol NO center dot, 6 fmol ONOO-, and 5 fmol NO2-) together with a comparatively small quantity of H2O2 (2 fmol). These species resulted from the primary production of 13 fmol for O-2(center dot-) and 28 fmol for NO center dot per single cell as reconstructed from the stoichiometries of the ROS and RNS releases. The high NO center dot/H2O2 and NO center dot/O-2(center dot-) ratios thus found are perfectly consistent with previous claims that the malignant bone formation ability of the osteosarcoma cells is related to a specific high production of NO center dot associated to a small one of O-2(center dot-)CNRS ; ENS ; UPMC [UMR 8640]; ANR [ANR-06-BLAN-029]; European Community [CP-FP214566-2]; NSFC [20620130427, 20773100]; MOST [2007DFC40440]; 973-Program [2007CB935603]; French Ministry of Research (MESR

État de la recherche sur le « fait villageois » en Picardie méridionale. Nouvelles données et nouvelles perspectives

Les principaux constats soulignés dans l’article-bilan sur « les campagnes médiévales en Picardie : État de la question » publié par la Revue archéologique de Picardie (Blary et al., 2005) faisaient état d’un manque cruel de synthèses sur l’habitat rural et le « fait villageois », de sa plus simple expression à sa complexité environnementale. Il pointait du doigt le manque de synergie dans la recherche, la dichotomie entre le nombre de faits observés et celui des faits publiés, la faiblesse d..