1,268 research outputs found
Unexpected effect of copper ions on electrochemical impedance behaviour of self-assembled alkylaminethiol monolayer
Effect of copper ions on the electrochemical behaviour of an alkylaminethiol monolayer has been studied by electrochemical impedance spectrosocpy. RAMAN experiment shows the effective adsorption of receptor onto the gold surfaces. The study of Nyquist plot shows that the gold/monolayer/electrolyte interface can be described by a serial combination of two R, CPE electrical circuits. In the presence of increasing amounts of copper, the Nyquist plots at low frequencies were modified showing an increase of the resistance of the second R, CPE electrical circuit. Moreover, this increase of resistance varies linearly with the amounts of copper ions added in solution from 10−8 mol·L−1 to 10−5 mol·L−1
Citoyens penseurs et politiques pensées. Les récits de rumeur
Commençons par une distinction simple, mais robuste : le rapport des rumeurs à la politique est contingent, celui des rumeurs au politique est essentiel. Autrement dit, les rumeurs prennent occasionnellement pour objet un personnage ou une situation politiques, tout comme elles peuvent prendre occasionnellement pour objet une question sanitaire, territoriale ou morale. Les exemples, on le sait, sont infiniment variés. Mais dans tous les cas, les rumeurs renvoient nécessairement à la position ..
The brain signature of paracetamol in healthy volunteers: a double-blind randomized trial
International audienceBackground: Paracetamol’s (APAP) mechanism of action suggests the implication of supraspinal structures but no neuroimaging study has been performed in humans.Methods and results: This randomized, double-blind, crossover, placebo-controlled trial in 17 healthy volunteers (NCT01562704) aimed to evaluate how APAP modulates pain-evoked functional magnetic resonance imaging signals. We used behavioral measures and functional magnetic resonance imaging to investigate the response to experimental thermal stimuli with APAP or placebo administration. Region-of-interest analysis revealed that activity in response to noxious stimulation diminished with APAP compared to placebo in prefrontal cortices, insula, thalami, anterior cingulate cortex, and periaqueductal gray matter.Conclusion: These findings suggest an inhibitory effect of APAP on spinothalamic tracts leading to a decreased activation of higher structures, and a top-down influence on descending inhibition. Further binding and connectivity studies are needed to evaluate how APAP modulates pain, especially in the context of repeated administration to patients with pain
RNA Pull-down Procedure to Identify RNA Targets of a Long Non-coding RNA
International audienceLong non-coding RNA (lncRNA), which are sequences of more than 200 nucleotides without a defined reading frame, belong to the regulatory non-coding RNA's family. Although their biological functions remain largely unknown, the number of these lncRNAs has steadily increased and it is now estimated that humans may have more than 10,000 such transcripts. Some of these are known to be involved in important regulatory pathways of gene expression which take place at the transcriptional level, but also at different steps of RNA co-and post-transcriptional maturation. In the latter cases, RNAs that are targeted by the lncRNA have to be identified. That's the reason why it is useful to develop a method enabling the identification of RNAs associated directly or indirectly with a lncRNA of interest. This protocol, which was inspired by previously published protocols allowing the isolation of a lncRNA together with its associated chromatin sequences, was adapted to permit the isolation of associated RNAs. We determined that two steps are critical for the efficiency of this protocol. The first is the design of specific anti-sense DNA oligonucleotide probes able to hybridize to the lncRNA of interest. To this end, the lncRNA secondary structure was predicted by bioinformatics and anti-sense oligonucleotide probes were designed with a strong affinity for regions that display a low probability of internal base pairing. The second crucial step of the procedure relies on the fixative conditions of the tissue or cultured cells that have to preserve the network between all molecular partners. Coupled with high throughput RNA sequencing, this RNA pull-down protocol can provide the whole RNA interactome of a lncRNA of interest
Classification of Supersymmetric Flux Vacua in M Theory
We present a comprehensive classification of supersymmetric vacua of M-theory
compactification on seven-dimensional manifolds with general four-form fluxes.
We analyze the cases where the resulting four-dimensional vacua have N =
1,2,3,4 supersymmetry and the internal space allows for SU(2), SU(3) or G_2
structures. In particular, we find for N = 2 supersymmetry, that the external
space-time is Minkowski and the base manifold of the internal space is
conformally K\"ahler for SU(2) structures, while for SU(3) structures the
internal space has to be Einstein-Sasaki and no internal fluxes are allowed.
Moreover, we provide a new vacuum with N = 1 supersymmetry and SU(3) structure,
where all fluxes are non-zero and the first order differential equations are
solved.Comment: 50 pages, clarification of the spinor ansatz added, references added,
typos correcte
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