Suspended microchannel resonators (SMRs) are resonant mass sensors that contain liquid within the mechanical structure, therefore minimizing damping associated with the fluidic viscous drag. In this ...paper, we present a novel fabrication process for transparent SMRs with integrated piezoelectric (PZE) transduction, based on thin film depositions and trench filling. Our method allows to finely tune the geometry and the dimensions of the embedded channels, through a short and well-controlled wet etching in KOH. After channel definition, the wafer has a flat surface that enables further microfabrication processing. Piezoelectric (PZE) electrodes are placed on top of each resonator, enabling independent transduction of the devices. Devices are fabricated with a yield higher than 95%, and characterized with and without fluids (water and IPA). PZE-transduced SMRs show a mass responsivity up to 1125±0.06mHz/pg and a non-monotonic dependence of the quality factor on fluidic viscosity. Besides PZE actuation and readout, our fabrication process is compatible with the integration of other types of transducers in close proximity to the fluid, broadening the spectrum of potential applications.
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Micro and Nano Electro Mechanical systems (M/NEMS) have a lot of potential to be used for sensing in different schemes and operation modes. We focus here on the use of coupled resonators for sensing ...and address the major limitation that these systems face, which stems from a compromise between dynamic range and responsivity. When the system becomes unbalanced, the responsivity drops. To solve this issue, we propose the use of piezoelectric-based stress tuning of the stiffness of the resonators in order to rebalance the system of resonators. With this approach we expect to be able to extend the dynamic range of such systems by some orders of magnitude.
Les épilepsies focales structurelles pharmacorésistantes avec crises pariétales représentent seulement 5 % des séries chirurgicales et moins de 10 % dans notre série de patients explorés en SEEG à ...Nancy. Ce sont des épilepsies de diagnostic difficile du fait de leur rareté et d’une symptomatologie riche témoignant d’une implication extrapariétale. Le diagnostic localisateur des crises peut donc être retardé voire conduire à une localisation erronée de la zone épileptogène.
À partir des corrélations anatomo-électrocliniques en SEEG, déterminer les signes critiques associés à la décharge critique pariétale initiale et à la propagation pariétale et extrapariétale.
Étude de deux patients implantés en SEEG présentant une épilepsie pariétale pharmacorésistante. Analyse de l’activité paroxystique enregistrée et de la clinique lors de la crise enregistrée en simultanée en vidéo.
La première patiente présente une symptomatologie sensitive unilatérale associée à une décharge limitée au cortex post-central. Le second patient présente une activité motrice dystonique et hyperkinétique concomitante d’une décharge pariétale avec une propagation lente intrapariétale (26 s) puis secondairement une propagation extrapariétale asymétrique (frontal ipsilatéral), contrairement aux crises frontales qui se caractérisent par une propagation bilatérale rapide.
Ces deux observations permettent de mettre évidence un pattern électroclinique orientant vers le lobe pariétal aussi bien au niveau des signes que de la dynamique. Ces conclusions sont à confirmer sur une série de patient plus importante.
This feature article concerns Pt surfaces modified (decorated) by ruthenium as model fuel cell electrocatalysts for electrooxidation processes. This work reveals the role of ruthenium promoters in ...enhancing electrocatalytic activity toward organic fuels for fuel cells, and it particularly concerns the methanol decomposition product, surface CO. A special focus is on surface mobility of the CO as it is catalytically oxidized to CO2. Different methods used to prepare Ru-decorated Pt single crystal surfaces as well as Ru-decorated Pt nanoparticles are reviewed, and the methods of characterization and testing of their activity are discussed. The focus is on the origin of peak splitting involved in the voltammetric electrooxidation of CO on Ru-decorated Pt surfaces, and on the interpretative consequences of the splitting for single crystal and nanoparticle Pt/Ru bimetallic surfaces. Apparently, screening through the literature allows formulating several models of the CO stripping reaction, and the validity of these models is discussed. Major efforts are made in this article to compare the results reported by the Urbana-Champaign group and the Munich group, but also by other groups. As electrocatalysis is progressively more and more driven by theory, our review of the experimental findings may serve to summarize the state of the art and clarify the roads ahead. Future studies will deal with highly dispersed and reactive nanoscale surfaces and other more advanced catalytic materials for fuel cell catalysis and related energy applications. It is expected that the metal/metal and metal/substrate interactions will be increasingly investigated on atomic and electronic levels, with likewise increasing participation of theory, and the structure and reactivity of various monolayer catalytic systems involving more than two metals (that is ternary and quaternary systems) will be interrogated.
This study aimed to develop consensus on an internationally agreed dataset for juvenile dermatomyositis (JDM), designed for clinical use, to enhance collaborative research and allow integration of ...data between centres.
A prototype dataset was developed through a formal process that included analysing items within existing databases of patients with idiopathic inflammatory myopathies. This template was used to aid a structured multistage consensus process. Exploiting Delphi methodology, two web-based questionnaires were distributed to healthcare professionals caring for patients with JDM identified through email distribution lists of international paediatric rheumatology and myositis research groups. A separate questionnaire was sent to parents of children with JDM and patients with JDM, identified through established research networks and patient support groups. The results of these parallel processes informed a face-to-face nominal group consensus meeting of international myositis experts, tasked with defining the content of the dataset. This developed dataset was tested in routine clinical practice before review and finalisation.
A dataset containing 123 items was formulated with an accompanying glossary. Demographic and diagnostic data are contained within form A collected at baseline visit only, disease activity measures are included within form B collected at every visit and disease damage items within form C collected at baseline and annual visits thereafter.
Through a robust international process, a consensus dataset for JDM has been formulated that can capture disease activity and damage over time. This dataset can be incorporated into national and international collaborative efforts, including existing clinical research databases.
tDCS is a widely investigated noninvasive neuromodulation technic in neurological and psychiatric disorders. Some studies demonstrate the effect of tDCS on interictal epileptiform discharges (IED) ...(Fregni et al., 2006).
The objective of our study was to investigate the tDCS effect on IED (frequency of occurrence and amplitudes) in intracerebral structures thanks to SEEG investigation.
Two patients with focal drug-resistant epilepsy were included: one medial and one lateral temporal lobe epilepsy. In average, they were implanted with 15 SEEG electrodes. Thanks to the SEEG recordings (5 days), epileptologists localized the irritative zone. The experiment was divided in 3 sessions: 20min sham, then 20min tDCS (−1mA) and finaly 20min sham. The amplitudes and the number of occurrences were analyzed. The results were compared between the sessions.
For the medial temporal lobe study, 64 and 33 IED were detected respectively before and after tDCS. The averaged amplitudes in the hippocampus were respectively 742±422μV and 152±43μV correspond to a 20% decrease (P<0.001; Mann–Whitney U test). For the lateral temporal lobe study, we detected respectively 192 and 165 discharges. The averaged amplitudes in the superior temporal gyrus were respectively 136±55μV and 117±36μV correspond to a 14% decrease (P<0.001; Mann–Whitney U test).
In this study, we demonstrated that the cathodal tDCS can reduce the number and the amplitude of epileptic discharges in intracerebral structures. The strength of this study is related to the simultaneous SEEG recordings with non-invasive tDCS and the in-vivo human brain investigation (deep and superficial).
Aims: This study investigates the antimicrobial activity and mode of action of two natural products, eugenol and thymol, a commonly utilized biostatic agent, triclocarban (TCC), and two surfactants, ...didecyldimethylammonium chloride (DDDMAC) and C10–C16 alkyldimethyl amine N‐oxides (ADMAO).
Methods and Results: Methods used included: determination of minimum inhibitory concentrations (MICs), lethal effect studies with suspension tests and the investigation of sub‐MIC concentrations on growth of E. coli, Staph. aureus and Ps. aeruginosa using a Bioscreen microbiological analyser. Leakage of intracellular constituents and the effects of potentiating agents were also investigated. Only DDDMAC was bactericidal against all of the organisms tested. Eugenol, thymol and ADMAO showed bacteriostatic and bactericidal activity, but not against Ps. aeruginosa. TCC was only bacteristatic against Staph. aureus, but like the other agents, it did affect the growth of the other organisms in the Bioscreen experiments. All of the antimicrobial agents tested were potentiated by the permeabilizers to some extent and leakage of potassium was seen with all of the agents except TCC.
Conclusions: DDDMAC was bactericidal against all organisms tested and all compounds had some bacteriostatic action. Low level static effects on bacterial growth were seen with sub‐MIC concentrations. Membrane damage may account for at least part of the mode of action of thymol, eugenol, DDDMAC and ADMAO.
Significance and Impact of the Study: The ingredients evaluated demonstrated a range of bactericidal and bacteriostatic properties against the Gram‐negative and ‐positive organisms evaluated and the membrane (leakage of intracellular components) was implicated in the mode of action for most (except TCC). Sub‐MIC levels of all ingredients did induce subtle effects on the organisms which impacted bacterial growth, even for those which had no true inhibitory effects.
•Mass spectrometry metabolic fingerprinting has been successfully applied to cheese.•A model cheese was inoculated with a strain of Lactococcus lactis.•Fingerprints significantly changed over time.•A ...large diversity of cheese metabolites was identified from MS fingerprints.•MS metabolic fingerprinting appears as a comprehensive and sensitive approach.
Metabolic fingerprinting is an untargeted approach which has not yet been undertaken to investigate cheese. This study is a proof of concept, concerning the ability of mass spectrometry (MS) metabolic fingerprinting to investigate modifications induced by bacterial metabolism in cheese over time. An ultrafiltrated milk concentrate was used to manufacture model cheeses inoculated with Lactococcus lactis LD61. Metabolic fingerprints were acquired after 0, 8 and 48h from two different fractions of the metabolome: the water-soluble fraction using liquid chromatography–high resolution-MS and a volatile fraction using gas chromatography–MS. Metabolic fingerprints differed significantly over time. Forty-five metabolites were identified, including well-known cheese metabolites, such as 12 amino acids and 25 volatile metabolites, and less studied ones, such as four vitamins, uric acid, creatine and l-carnitine. These results showed the relevance of cheese MS fingerprinting to generate new findings and to detect even slight differences between two conditions.
The link between cofactor binding and protein activity is well-established. However, how cofactor interactions modulate folding of large proteins remains unknown. We use optical tweezers, clustering ...and global fitting to dissect the folding mechanism of Drosophila cryptochrome (dCRY), a 542-residue protein that binds FAD, one of the most chemically and structurally complex cofactors in nature. We show that the first dCRY parts to fold are independent of FAD, but later steps are FAD-driven as the remaining polypeptide folds around the cofactor. FAD binds to largely unfolded intermediates, yet with association kinetics above the diffusion-limit. Interestingly, not all FAD moieties are required for folding: whereas the isoalloxazine ring linked to ribitol and one phosphate is sufficient to drive complete folding, the adenosine ring with phosphates only leads to partial folding. Lastly, we propose a dCRY folding model where regions that undergo conformational transitions during signal transduction are the last to fold.
Determining the degradation mechanisms of oxygen evolution reaction (OER) catalysts is fundamental to design improved proton-exchange membrane water electrolyzer (PEMWE) devices but remains ...challenging under the demanding conditions of PEMWE anodes. To address this issue, we introduce a methodology combining identical-location transmission electron microscopy (IL-TEM), X-ray photoelectron spectroscopy (XPS), and electrochemical measurements, and apply it to iridium nanoparticles (NPs) covered by a thin oxide layer (IrO x ) in OER conditions. The results show that, whatever the initial OER activity of the IrO x nanocatalysts, it gradually declines and reaches similar values after 30 000 potential cycles between 1.20 and 1.60 V versus the reversible hydrogen electrode (RHE). This drop in OER activity was ascribed to the progressive increase of the Ir oxidation state (fast change during electrochemical conditioning, milder change during accelerated stress testing) along with the increased concentrations of hydroxyl groups and water molecules. In contrast, no change in the mean oxidation state, no change in the hydroxyl/water coverage, and constant OER activity were noticed on the benchmark micrometer-sized IrO2 particles. In addition to chemical changes, Ir dissolution/redeposition and IrO x nanoparticle migration/agglomeration/detachment were made evident during the conditioning stage and in OER conditions, respectively. By combining the information derived from IL-TEM images and XPS measurements, we show that Ir(III) and Ir(V) are the best performing Ir valencies for the OER. These findings provide insights into the long-term OER activity of IrO x nanocatalysts as well as practical guidelines for the development of more active and more stable PEMWE anodes.
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