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Objective: Differences in type 2 diabetes phenotype by age are described, but it is not known whether these differences are seen in a more uniformly defined adult population at a common early stage of care. We characterize age-related clinical and metabolic characteristics of adults with type 2 diabetes on metformin monotherapy, prior to treatment intensification. Research Design and Methods: The Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness (GRADE) Study enrolled participants with type 2 diabetes duration ≥65 years) using ANOVA and Pearson’s chi-squared tests.. Results: Within the GRADE cohort (n=5,047), we observed significant differences by age with younger adults having greater racial diversity, fewer medications for common comorbidities, lower prevalence of CVD, higher weight and BMI, more pronounced hyperglycemia and diabetic dyslipidemia, with metabolic profile indicating lower insulin sensitivity (1/fasting insulin, HOMA-2S, Matsuda index) and inadequate β cell response (oral disposition index) (p < 0.05 across age categories). Conclusions: Clinical and metabolic characteristics of type 2 diabetes differ by age within the GRADE cohort. Younger adults exhibit more prominent obesity-related characteristics, including higher obesity levels, lower insulin sensitivity and beta cell compensation. Given the increasing burden of type 2 diabetes and complications, particularly among younger populations, these age-related distinctions may inform risk factor management approaches and treatment priorities. Further study will determine whether age-related differences impact response to therapy.

International audience; Wireless electrochemical systems constitute a rapidly developing field. Herein, photo-induced electrochemiluminescence (PECL) is studied at Si-based closed bipolar electrodes (BPEs) for designing anti-Stokes systems that can convert IR into visible photons, without direct electrical contact. We show that protection of the anodic emitting pole of the BPE allows the triggering of bright and longstanding emission under the synergetic actions of an external bias and IR illumination. Photoactive nand p-type Si BPEs are studied with front-side and backside illumination, respectively, and non-photoactive n +-Si BPEs are studied in the dark. Two electrochemiluminescent (ECL) systems ([Ru(bpy) 3 ] 2+ /TPrA and L-012) are tested and we show that the onset bias and the anti-Stokes shift can be controlled by the ECL system that is employed. These advances, rationalized by simulations, will be useful for the design of original PECL systems for chemical sensing or photodetection.

Vegetation attenuates the microwave emission from the land surface. The strength of this attenuation is quantified in models in terms of the parameter vegetation optical depth (VOD) and is influenced by the vegetation mass, structure, water content, and observation wavelength. Earth observation satellite sensors operating in the microwave frequencies are used for global VOD retrievals, enabling the monitoring of vegetation at large scales. VOD has been used to determine above-ground biomass, monitor phenology, or estimate vegetation water status. VOD can be also used for constraining land surface models or modelling wildfires at large scales. Several VOD products exist, differing by frequency/wavelength, sensor, and retrieval algorithm. Numerous studies present correlations or empirical functions between different VOD datasets and vegetation variables such as the normalized difference vegetation index, leaf area index, gross primary production, biomass, vegetation height, or vegetation water content. However, an assessment of the joint impact of land cover, vegetation biomass, leaf area, and moisture status on the VOD signal is challenging and has not yet been done. This study aims to interpret the VOD signal as a multi-variate function of several descriptive vegetation variables. The results will help to select VOD at the most suitable wavelength for specific applications and can guide the development of appropriate observation operators to integrate VOD with large-scale land surface models. Here we use VOD from the Land Parameter Retrieval Model (LPRM) in the Ku, X, and C bands from the harmonized Vegetation Optical Depth Climate Archive (VODCA) dataset and L-band VOD derived from Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active Passive (SMAP) sensors. The leaf area index, live-fuel moisture content, above-ground biomass, and land cover are able to explain up to 93 % and 95 % of the variance (Nash–Sutcliffe model efficiency coefficient) in 8-daily and monthly VOD within a multi-variable random forest regression. Thereby, the regression reproduces spatial patterns of L-band VOD and spatial and temporal patterns of Ku-, X-, and C-band VOD. Analyses of accumulated local effects demonstrate that Ku-, X-, and C-band VOD are mostly sensitive to the leaf area index, and L-band VOD is most sensitive to above-ground biomass. However, for all VODs the global relationships with vegetation properties are non-monotonic and complex and differ with land cover type. This indicates that the use of simple global regressions to estimate single vegetation properties (e.g. above-ground biomass) from VOD is over-simplistic.

Living systems that can spontaneously exhibit directional motion belong to diverse classes such as bacteria, sperm and plankton. They have fascinated scientists in recent years to design completely artificial or biohybrid mobile objects. Natural ingredients, like parts of plants, have been used to elaborate miniaturized dynamic objects, which can move when they are combined with other, non-natural, building blocks. Herein, we report that the precise structural tailoring of natural plant leaves allows generating a spatially predefined and confined release of oxygen gas, due to the conversion of carbon dioxide. This constitutes the driving force for generating motion, which is solely due to the respiration of leaves by photosynthesis. The rate of gas evolution can be fine-tuned by changing the light intensity and the leaf size, allowing ultimately to control the motility of objects with dimensions ranging from the millimeter to the micrometer scale.

The design of efficient chiral catalysts is of crucial importance since it allows generating enantiomerically pure compounds. Tremendous efforts have been made over the past decades regarding the development of materials with enantioselective properties for various potential applications ranging from sensing to catalysis and separation. Recently, chiral features have been generated in mesoporous metals. Although these monometallic matrices show interesting enantioselectivity, they suffer from rather low stability, constituting an important roadblock for applications. Here, a straightforward strategy to circumvent this limitation by using nanostructured platinum-iridium alloys is presented. These materials can be successfully encoded with chiral information by co-electrodeposition from Pt and Ir salts in the simultaneous presence of a chiral compound and a lyotropic liquid crystal as asymmetric template and mesoporogen, respectively. The alloys enable a remarkable discrimination between chiral compounds and greatly improved enantioselectivity when used for asymmetric electrosynthesis (>95 %ee), combined with high electrochemical stability., Tremendous efforts have been made over the past decades regarding the development of materials with enantioselective properties. Here, the authors present a nanostructured chiral imprinted metal alloy that exhibits high enantioselectivity and stability for the electrosynthesis of chiral molecules.

The electric motor production of the automotive industry faces numerous challenges due to weak sales and uncertain sales forecasts of the electric vehicle. To meet these challenges, scalable production systems have increasingly been set up. The application of virtual commissioning to scalable production systems holds increased potential since the deterministic simulation model can be improved step by step through the inclusion of real data. Therefore, a concrete process model is to be created describing how virtual commissioning can be made even more effective through real data connection. The validation is carried out on an application from material handling technology.

A series of mono-, di-, and tri-topic receptors, in which H-bonding sites, complementary to those of barbituric acid (BA), are fused, is used to induce the supramolecular assembly of n x m ladders containing 1, 2, or 3 triphenylenevinylene units appended with BA. The topological constraint enforced by the architectures induces through-space interactions between the electroactive moieties that are reflected in the electronic absorption and emission spectrum. The n =2, m =2 or m =3 architectures undergo two single electron oxidation events indicative of the formation of the corresponding mono- and di-radical cation species with comproportionation constants of 340 and 70, respectively. Comparison of the electrochemical potentials suggests that the charges are delocalized over the electroactive units in the assembly.

This work is dedicated to a multi-scale modelling of coupled diffusion and reaction in a porous microelectrode operating in the Direct Electron Transfer mode. The pore-scale physico-electrochemical unsteady model is developed considering the oxygen reduction, catalyzed by an enzyme coating the pores of the electrode, coupled to the diffusion of oxygen and mass balance of enzymes. This model is formally upscaled to obtain an original closed unsteady macroscopic model operating at the electrode scale, together with the associated closure providing the effective diffusivity tensor. A validation of this model is carried out from a comparison with the solution of the initial 3D pore-scale governing equations considering the bilirubin oxydase as the catalyst. The relevance and accuracy of the macroscale model are proved allowing a considerable simulation speedup. It is further employed to successfully predict experimental voltammetry results obtained with porous gold electrodes functionnalized with a bilirubin oxidase mutant (BOD S362C). This model represents a breakthrough by providing an operational simple way of understanding and further optimizing porous electrodes functioning in DET mode.

International audience; Conducting polymers have been extensively studied due to their potential applications ranging from sensing to energy storage and environmental remediation. They can be easily generated by electrosynthesis and have also very interesting electrochemical features, which have been mostly examined with classic electrochemical approaches. Bipolar electrochemistry offers an attractive alternative way to synthesize and characterize the physico-chemical properties of conducting polymers. The wireless and asymmetric features of bipolar electrochemistry can be advantageously combined with the electroactivity, tunability and easy processability of conducting polymers. This synergy has been increasingly explored in recent years for the controlled electrogeneration, surface modification and characterization of different π-conjugated polymers. This review summarizes the advances in this context and discusses also some unconventional applications such as wireless light-emitting devices and actuators.

International audience; Chirality governs many chemical and biological processes, since most active substances are chiral. Enantiomers are mirror images of the same molecule that can exhibit significant differences in terms of biochemical activity, toxicity and transport mechanisms in the human body. Thus, developing effective methods to achieve chiral recognition is of great significance and has been a hot topic in chemo/biological studies. In recent years, electrochemical methods have received considerable attention in this field since they can offer several advantages over chromatographic or spectroscopic methods. In this review, a comprehensive and critical description of the trends in electrochemical chiral recognition over the last five years is presented. In addition, some unconventional electrochemical methods for the transduction of chirality at different length scales are described and discussed.

International audience; Bipolar electrochemistry can be employed in the context of chiral recognition in order to obtain useful analytical readouts of enantiomeric analytes. Herein, we employ this concept for the simultaneous determination of two enantiomers present in solution, and its possible use as transduction mechanism for complex real matrices analysis. This approach is based on the combination of the enantioselective electrooxidation of only one of the two antipodes of a chiral analyte with the emission of light from light-emitting diodes (LEDs). A double hybrid device was designed, using the enantiomers of an inherently chiral oligomer and a bare gold wire as the anode and cathode of a green and red LED. By applying an appropriate voltage, the wirelessly induced redox reactions trigger light emission only when the probe with the right configuration is present in solution. This device was used to simultaneously measure the ratio between Land D-Tryptophan, both present in the same solution and to quantify L-ascorbic acid in a commercial juice sample. The measurement correlates with the value reported on the sample specifications. These results illustrate the possible use of such light emitting bipolar devices as analytical tools for qualitative and quantitative measurements of enantiomeric excess, even in real samples.

In this work, bipolar electrochemistry is used to perform wireless indirect electrodeposition of two different polymer coatings on both sides of carbon nanotube arrays. Using a thermoresponsive hydrogel on one side and an inert insoluble polymer on the other side, it is possible to generate, in a single step, a nanoporous reservoir with Janus character closed on one side by a thermoresponsive membrane. The thermoresponsive polymer, poly(N-isopropylacrylamide) (pNIPAM), is generated by the local reduction of persulfate ions, which initiates radical polymerization of NIPAM. Electrophoretic paint (EP) is chosen as an inert polymer. It is deposited by precipitation because of a local decrease in pH during water oxidation. Both polymers can be deposited simultaneously on opposite sides of the bipolar electrode during the application of the electric field, yielding a double-modified Janus object. Moreover, the length and thickness of the polymer layers can be controlled by varying the electric field and the deposition time. This concept is applied to vertically aligned carbon nanotube arrays (VACNTs), trapped inside an anodic aluminum oxide membrane, which can further be used as a smart reservoir for chemical storage and release. A fluorescent dye is loaded in the VACNTs and its release is studied as a function of temperature. Low temperature, when the hydrogel layer is in the swollen state, allows diffusion of the molecule. Dye release occurs on the hydrogel-modified side of the VACNTs. At high temperatures, when the hydrogel layer is in the collapsed state, dye release is blocked because of the impermeability of the pNIPAM layer. This concept paves the way toward the design of advanced devices in the fields of drug storage and directed delivery.

International audience; The rapid generation of material libraries with multidimensional gradients is important for the discovery of new functional materials. Here we report an integrated fabrication scheme, based on glancing angle physical vapor deposition, to form a thin-film materials library with controlled variations in nanoshape, multinary composition, and oxidation state on a single large area substrate. We demonstrate the versatility of the method by growing an octonary materials system, which we characterize with high-throughput methods, and reveal variations in several physico-chemical properties. Among others, we examine the materials library in the frame of the oxygen evolution reaction and show that nanostructuring leads to NiO clusters that are active towards such a reaction. Our scheme can be readily extended to include more starting elements, and can be transferred to other deposition methods, making this an adaptable and versatile platform for combinatorial materials science.

International audience; Electrochemical regeneration of reduced nicotinamide adenine dinucleotide (NADH) is an extremely important challenge for the electroenzymatic synthesis of many valuable chemicals. Although some important progress has been made with modified electrodes concerning the reduction of NAD+, the scale-up is difficult due to mass transport limitations inherent to large-size electrodes. Here, we propose instead to employ a dispersion of electrocatalytically active modified microparticles in the bulk of a bipolar electrochemical cell. In this way, redox reactions occur simultaneously on all of these individual microelectrodes without the need of a direct electrical connection. The concept is validated by using [Rh(Cp*)(bpy)Cl]+ functionalized surfaces, either of carbon felt as a reference material, or carbon microbeads acting as bipolar objects. In the latter case, enzymatically active 1,4-NADH is electroregenerated at the negatively polarized face of the particles. The efficiency of the system can be fine-tuned by controlling the electric field in the reaction compartment and the number of dispersed microelectrodes. This wireless bioelectrocatalytic approach opens up very interesting perspectives for electroenzymatic synthesis in the bulk phase.

International audience; Autonomous swimmers have been intensively studied in recent years due to their numerous potential applications in many areas, ranging from biomedicine to environmental remediation. Their motion is based either on different self-propulsion mechanisms or on the use of various external stimuli. Herein, the synergy between the ion flux around self-electrophoretic Mg/Pt Janus swimmers and an external magnetic field is proposed as an efficient alternative mechanism to power swimmers based on the resulting Lorentz force. A strong magnetohydrodynamic effect is observed due to the orthogonal combination of magnetic field and spontaneous ionic currents, leading reciprocally to an increase of the swimmer speed by up to two orders of magnitude. Furthermore, the trajectory of the self-propelled swimmers can be controlled by the orientation of the magnetic field, due to the presence of an additional torque force caused by a vertical cation flux along the swimmer edges, resulting in predictable clockwise or anticlockwise motion. In addition, this effect is independent of the swimmer size, since a similar type of chiral motion is observed for macro-and microscale objects.

This contribution reviews a selection of the most recent studies on the use of bipolar electrochemistry in the framework of analytical chemistry. Despite the fact that the concept is not new, with several important studies dating back to the middle of the last century, completely novel and very original approaches have emerged over the last decade. This current revival illustrates that scientists still (re)discover some exciting virtues of this approach, which are useful in many different areas, especially for tackling analytical challenges in an unconventional way. In several cases, this “wireless” electrochemistry strategy enables carrying out measurements that are simply not possible with classic electrochemical approaches. This review will hopefully stimulate new ideas and trigger scientists to integrate some aspects of bipolar electrochemistry in their work in order to drive the topic into yet unexplored and eventually completely unexpected directions.

International audience; Numerous artificial micro-and nanomotors, as well as various swimmers have been inspired by living organisms that are able to move in a coordinated manner. Their cooperation has also gained a lot of attention because the resulting clusters are able to adapt to changes in their environment and to perform complex tasks. However, mimicking such a collective behavior remains a challenge. In the present work, magnesium microparticles are used as chemotactic swimmers with pronounced collective features, allowing the gradual formation of macroscopic agglomerates. The formed clusters act like a single swimmer able to follow pH gradients. This dynamic behavior can be used to spot in a straightforward way localized corrosion events. The autonomous docking of the swimmers to the corrosion site leads to the formation of a local protection layer, thus increasing corrosion resistance and triggering partial self-healing.

The seasonal and longer-term dynamics of fuel accumulation affect fire seasonality and the occurrence of extreme wildfires. Failure to account for their influence may help to explain why state-of-the-art fire models do not simulate the length and timing of the fire season or interannual variability in burnt area well. We investigated the impact of accounting for different timescales of fuel production and accumulation on burnt area using a suite of random forest regression models that included the immediate impact of climate, vegetation, and human influences in a given month and tested the impact of various combinations of antecedent conditions in four productivity-related vegetation indices and in antecedent moisture conditions. Analyses were conducted for the period from 2010 to 2015 inclusive. Inclusion of antecedent vegetation conditions representing fuel build-up led to an improvement of the global, climatological out-of-sample R 2 from 0.579 to 0.701, but the inclusion of antecedent vegetation conditions on timescales ≥ 1 year had no impact on simulated burnt area. Current moisture levels were the dominant influence on fuel drying. Additionally, antecedent moisture levels were important for fuel build-up. The models also enabled the visualisation of interactions between variables, such as the importance of antecedent productivity coupled with instantaneous drying. The length of the period which needs to be considered varies across biomes; fuel-limited regions are sensitive to antecedent conditions that determine fuel build-up over longer time periods (∼ 4 months), while moisture-limited regions are more sensitive to current conditions that regulate fuel drying.

International audience; Miniaturized autonomous swimmers have become more and more important in many areas of research due to various fields of use, ranging from biomedical to environmental tasks. Precise and predictable control of their trajectories is a key ingredient for increasing their application potential. This can be typically achieved by using external forces such as magnetic or electric fields. An interesting alternative is to use intrinsic features of the swimmers, which allow them to exhibit chemotaxis. Such a built-in “intelligence” enables more complex trajectories, relying on mechanisms that can be considered very basic analogs of decision-making processes. Herein, autonomous light-emitting chemoelectronic swimmers are presented that are able to navigate along trajectories with increasing complexity. Their decision-making capacities are characterized by recording the light emitted along their path by a fully integrated light-emitting diode. Chemotaxis is found to be the main driving force behind their behavior, allowing envisioning such systems for solving complex maze patterns.

We report the x-ray crystal structure of intact, full-length human immunoglobulin (IgG4) at 1.8 A resolution. The data for IgG4 (S228P), an antibody targeting the natriuretic peptide receptor A, show a previously unrecognized type of Fab-Fc orientation with a distorted λ-shape in which one Fab-arm is oriented toward the Fc portion. Detailed structural analysis by x-ray crystallography and molecular simulations suggest that this is one of several conformations coexisting in a dynamic equilibrium state. These results were confirmed by small angle x-ray scattering in solution. Furthermore, electron microscopy supported these findings by preserving molecule classes of different conformations. This study fosters our understanding of IgG4 in particular and our appreciation of antibody flexibility in general. Moreover, we give insights into potential biological implications, specifically for the interaction of human anti-natriuretic peptide receptor A IgG4 with the neonatal Fc receptor, Fcγ receptors, and complement-activating C1q by considering conformational flexibility.

We report on the facile solid-state synthesis and characterization of Li7SiPS8, a new member of the tetragonal Li10GeP2S12 (LGPS)-type family of ultrafast Li+ solid electrolytes. We analyze the structure, phase stability, and Li+ conductivity of tetragonal and orthorhombic LSiPS by pulsed field gradient NMR and impedance spectroscopy, which show conductivities at room temperature of up to 2 mS cm–1. Although ranking tetragonal LiSiPS as an ultrafast solid electrolyte, the observed conductivity is unexpectedly low compared to other members of this solid-solution system. Utilizing solid-state NMR, quantitative phase analysis, and impedance spectroscopy, we identify an amorphous thiophosphate side phase with low Si content, which limits the intergrain conductivity and, hence, a potentially higher total conductivity. This case study thus highlights the need for comprehensive structural analysis of LGPS-type materials beyond the crystalline fractions to fully characterize the structure–property relationships i...

The crystal structure of boron tetrathiophosphate BPS4 was reinvestigated using single-crystal X-ray diffraction. The structure shows unidimensional chains similar to SiS2 as structural motifs. BPS4 crystallizes in the orthorhombic space group Ibam (no. 72), with a = 5.6173(3), b = 8.9929(4), c = 5.2433(3) angstrom and V = 264.87(2) angstrom(3) and is closely related to the orthorhombic high-temperature modification of AlPS4 (ht-AlPS4). The SiS2-like chains are all oriented parallel to the c axis, which explains the needle-like morphology and that the crystals easily cleave to thinner needles under mechanical stress. While ht-AlPS4 shows an ordered Al-P sublattice, the B-P sublattice in BPS4 is substantially disordered. The thermal properties of BPS4 were investigated by DTA measurements and a detailed analysis of the Raman spectrum assisted by quantum mechanical calculations is presented. The crystallographic disorder in BPS4 is the result of inter-chain disorder, whereas local intra-chain ordering of B and P can be concluded from Raman spectroscopy.

Doping of a transition-metal dichalcogenide deposited onto a conducting surface acting as bipolar electrode was recently reported. Here, freestanding macro- and microscale transition-metal dichalcogenide substrates are successfully employed as effective bipolar electrodes without the need of using an additional conducting support. This is first demonstrated by achieving site-selective bipolar electrodeposition of several metals, such as gold, silver, copper, and nickel, on macroscale MoSe 2 substrates (typically 1 mm in size). Also, the superior efficiency of MoSe 2 compared to that of a carbon substrate toward hydrogen evolution reaction, well-known in conventional electrochemistry, is demonstrated in the bipolar electrochemistry configuration. Such electrocatalytic properties can be advantageously used by combining this reduction with a given oxidation reaction to ease the electrochemical coupling. Also, as a wireless technique, bipolar electrochemistry enables the simultaneous addressing of large ensembles of bipolar electrodes with a single pair of driving electrodes. Therefore, in a bulk experiment, a suspension composed of thousands of individual MoSe 2 microparticles (with a typical size of 20-80 μm) that are addressed simultaneously, is employed to significantly accelerate electrolysis. Amplex Red was selected as an oxidizable organic model dye. Such electrolysis occurs on the timescale of several seconds, which is definitely not achievable by addressing a single macroscale MoSe 2 bipolar electrode. This performance is due to the collective behavior of the ensemble of MoSe 2 bipolar electrodes because the oxidation process occurs simultaneously at each individual anodic pole., SCOPUS: ar.j, info:eu-repo/semantics/published

In the solid solution series Li2–xGe3+1/2xSb2Te7 and Li2–xGe11+1/2xSb2Te15 (0 ≤ x ≤ 2), the heterovalent substitution gradually changes the vacancy concentration on the cation position from 0% (for...

A key approach for designing bioinspired machines is to transfer concepts from nature to man-made structures by integrating biomolecules into artificial mechanical systems. This strategy allows the conversion of molecular information into macroscopic action. Here, we describe the design and dynamic behaviour of hybrid bioelectrochemical swimmers that move spontaneously at the air–water interface. Their motion is governed by the diastereomeric interactions between immobilized enantiopure oligomers and the enantiomers of a chiral probe molecule present in solution. These dynamic bipolar systems are able to convert chiral information present at the molecular level into enantiospecific macroscopic trajectories. Depending on the enantiomer in solution, the swimmers will move clockwise or anticlockwise; the concept can also be used for the direct visualization of the degree of enantiomeric excess by analysing the curvature of the trajectories. Deciphering in such a straightforward way the enantiomeric ratio could be useful for biomedical applications, for the read-out of food quality or as a more general analogue of polarimetric measurements. Self-propelled artificial chemical swimmers have previously been developed for chemical sensing. Now, hybrid bioelectrochemical swimmers, capable of translating chiral molecular information into macroscopic motion, have been developed. Diastereomeric interactions between enantiopure oligomers immobilized on the swimmer and a chiral molecule present in solution control the trajectory of the device.

Genome-wide transcriptomic analyses in whole tissues reflect the aggregate gene expression in heterogeneous cell populations comprising resident and migratory cells, and they are unable to identify cell type–specific information. We used a computational method (population-specific expression analysis [PSEA]) to decompose gene expression in gingival tissues into cell type–specific signatures for 8 cell types (epithelial cells, fibroblasts, endothelial cells, neutrophils, monocytes/macrophages, plasma cells, T cells, and B cells). We used a gene expression data set generated using microarrays from 120 persons (310 tissue samples; 241 periodontitis affected and 69 healthy). Decomposition of the whole-tissue transcriptomes identified differentially expressed genes in each of the cell types, which mapped to biologically relevant pathways, including dysregulation of Th17 cell differentiation, AGE-RAGE signaling, and epithelial-mesenchymal transition in epithelial cells. We validated selected PSEA-predicted, differentially expressed genes in purified gingival epithelial cells and B cells from an unrelated cohort ( n = 15 persons), each of whom contributed with 1 periodontitis-affected and 1 healthy gingival tissue sample. Differential expression of these genes by quantitative reverse transcription polymerase chain reaction corroborated the PSEA predictions and pointed to dysregulation of biologically important pathways in periodontitis. Collectively, our results demonstrate the robustness of the PSEA in the decomposition of gingival tissue transcriptomes and its ability to identify differentially regulated transcripts in particular cellular constituents. These genes may serve as candidates for further investigation with respect to their roles in the pathogenesis of periodontitis.

International audience; Bipolar electrochemistry has gained increasing attention in recent years as an attractive transduction concept in analytical chemistry in general, and more specifically in the frame of chiral recognition. Herein, we use this concept of wireless electrochemistry, based on the combination of the enantioselective oxidation of a chiral probe with the emission of light from a light emitting diode (LED), as an alternative for an easy and straightforward read-out of the presence of chiral molecules in solution. A hybrid polymer-microelectronic device was designed, using an inherently chiral oligomer i.e. oligo-(3,3’-dibenzothiophene) and a polypyrrole strip as the anode and cathode of a miniaturized LED. The wireless induced redox reactions trigger light emission when the probe with the right chirality is present in solution, whereas no light emission is observed for the opposite enantiomer. The average light intensity shows a linear correlation with the analyte concentration and the concept opens the possibility to quantify the enantiomeric excess in mixtures of the molecular antipodes.

International audience; Transduction of chiral information can be achieved at different length scales. Among all possible approaches, in this work, we propose a straightforward concept to transfer chiral features from the molecular level to the shape of macroscopic objects by combining the concepts of inherently chiral oligomers and bipolar electrochemistry. Hybrid freestanding lamellar films, composed of polypyrrole and the two oligomeric antipodes of a chiral monomer, are exposed in solution to a chiral target molecule (i.e.,l- and d-DOPA) in the presence of an electric field. This leads to an electrochemically induced deformation of the film, which in fine results in one or the other of two macroscopic enantiomorphs, depending on which stereoisomer is present in the solution.

International audience; Swimming lights: Light-emitting mobile systems, based on electrochemical approaches, offer interesting visualization strategies for potential applications ranging from remote sensing and optical imaging to controlled cargo manipulation and studies of complex collective behaviour such as swarming and schooling.

We employed the oxidative dehydrogenation of C2H2 by CO2 and the C2H2 decomposition to prepare carbon nanotubes (CNTs) and carbon nanofibers (CNFs). The use of a small amount of Ni catalyst made it possible to produce CNTs and CNFs having a highly defective structure at a relatively low temperature compared to the one typically used for the CNT synthesis. The synthesized CNTs and CNFs were decorated with about 10 nm-gold nanoparticles (AuNPs) via an electrostatic self-attachment. The electrode with CNTs synthesized via the C2H2–CO2 reaction exhibits superior electrochemical reactivity with H2O2 when compared to the ones with CNTs synthesized via C2H2 decomposition, commercial CNTs, CNFs, and other more common carbon supports e.g. carbon black and activated charcoal. It demonstrates a rapid response, high sensitivity (104.9 μA mM−1 cm−2), wide linear working range (5 μM–23 mM), low detection limit (0.138 μM), good selectivity, reproducibility, and stability. The CNTs synthesized via the C2H2–CO2 reaction are suggested as energy-saving, cost-effective and environmentally friendly supporting material candidates for practical applications. The electrodes with CNTs show a high electrochemically active surface area, low charge transfer resistance and fast mass transfer at the electrode surface that are key factors for H2O2 detection.

International audience; The combination of bipolar electrochemistry (BE), as a wireless electrochemical approach, and of electrochemiluminescence (ECL) as an imaging readout is a successful strategy with a wide range of analytical applications. However, small conductive entities such as micrometric and nanometric objects are particularly difficult to polarize by BE since they require extremely high electric fields. In order to circumvent this issue due to intrinsic limitations of BE, we elaborated a solid-state micropore, decorated with a rhombus-shaped gold microelectrode. The electric field strength was concentrated inside the solid-state micropore where the conductive gold microelectrode was precisely located and acted as a bipolar light-emitting device. This original configuration allowed achieving adequate polarization of the gold microelectrode in a wireless manner, which led locally to ECL emission. ECL imaging shows that light was generated by the bipolar microelectrode in the center of the micropore. ECL emission could be achieved by imposing a potential value (10 V) to the feeder electrodes that is more than 2 orders of magnitude lower than those required without the micropore. The reported ECL approach opens exciting perspectives for the development of original wireless bioanalytical applications and dynamic bipolar experiments with small objects passing through the pores.

The development of surfaces with chiral features is a fascinating challenge for modern materials science, especially when they are used for chiral separation technologies. In this contribution, the design of hierarchically structured chiral macroporous zeolitic imidazolate framework-8 (ZIF-8) electrodes is presented. They are elaborated by an electrochemical deposition-dissolution technique based on the electrodeposition of metal through a colloidal crystal template, followed by controlled electrooxidation. This generates locally metal cations, which can interact with a chiral ligand present in the solution to form metal-organic frameworks (MOFs). The macroporous structure facilitates the access of the chiral recognition sites, located in the mesoporous MOF, and thus helps to overcome mass transport limitations. The efficiency of the designed functional materials for chiral adsorption and separation can be fine-tuned by applying an adjustable electric potential to the electrode surfaces. This hierarchical chiral ZIF-8 structure was deposited at the walls of a microfluidic device and used as a stationary phase for enantioselective separation. The potential-controlled interaction between the stationary phase and the chiral analytes allows baseline separation of two enantiomers. This opens up interesting perspectives for using hierarchically structured chiral MOFs as an efficient material for the selective adsorption and separation of chiral compounds.

International audience; The advantage of using porous materials for biofuel cells and biosensors is their very large internal surface area (where electron exchange takes place) compared to the overall material volume, yielding much larger current densities than on a bare solid electrode of the same size. However, limitations occur because of mass transfer resistance through the pores. We describe here a bottom-up approach to optimize the design of such materials, through the analysis and modeling of their porous structure. Electrodes prepared by replicating stacked Langmuir-Blodgett films, with 1-µm diameter interconnected spherical pores, were studied. Since pore window dimensions are around 100 nm, Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM) has been performed to obtain a 3D reconstruction of the porous medium. Then, a determination of the geometrical characteristics has been achieved through image analysis. The structure of the sphere packing, the shape and size of the connections between spheres, the distances between spheres, the sphere diameters and the specific surface area have been analyzed. The porous medium is close to a face-centered cubic arrangement of spherical pores, but several deviations from ideality are present: missing pores (point defects), stacking errors (dislocations), and incomplete connection between spheres (only 50% of the ideal sphere connections are present). The consequence of such defects on transport are studied through image-based simulations of mass diffusion in the actual porous medium and in similar ideal media.

Asymmetrically modified Janus microparticles are presented as autonomous light emitting swimmers. The localized dissolution of hybrid magnesium/polymer objects allows combining chemiluminescence with the spontaneous production of H2 bubbles, and thus generating directed motion. These light-emitting microswimmers are synthesized by using a straightforward methodology based on bipolar electromilling, followed by indirect bipolar electrodeposition of an electrophoretic paint. An optimization of the experimental parameters enables in the first step the formation of well-defined isotropic or anisotropic Mg microparticles. Subsequently, they are asymmetrically modified by wireless deposition of an anodic paint. The degree of asymmetry of the resulting Janus particles can be fine-tuned, leading to a controlled directional motion due to anisotropic gas formation. This autonomous motion is coupled with the emission of bright orange light when Ru(bpy)32+ and S2O82− are present in the solution as chemiluminescent reagents. The light emission is based on an original process of interfacial redox-induced chemiluminescence, thus allowing an easy visualization of the swimmer trajectories., Asymmetrically modified Janus microparticles are presented as autonomous light emitting swimmers with shape-controlled trajectories.

International audience; Enzymatic reactions involving glucose hold the potential for building implantable biosensors and embedded power generators for various medical applications. While Biofuel cells (BFCs) such as enzymatic glucose/O2 are ensured to benefit from abundant chemical resources that can be harvested in the immediate environment of the human body, the highly critical in vivo kinetics of biofuel cell is not yet fully understood. Unfortunately, existing solutions for real-time monitoring of the reaction on rodents are not possible today, or too bulky, which has a biasing impact on the animal behavior. This work presents a light, battery-less, and wireless strategy to continuously monitor a BFC implanted in a laboratory rat using a Frequency Identification (RFID) link. An extremely lightweight and flexible tag antenna of footprint lower than 10 cm² is presented with communication capability above 60 cm in field environment. The operational capabilities are demonstrated with a 24-hour continuous monitoring of an enzymatic glucose/O2 reaction, both in vitro and in vivo.