Institution
École normale supérieure de Cachan
Education•Cachan, Île-de-France, France•
About: École normale supérieure de Cachan is a education organization based out in Cachan, Île-de-France, France. It is known for research contribution in the topics: Decidability & Nonlinear system. The organization has 2717 authors who have published 5585 publications receiving 175925 citations.
Papers published on a yearly basis
Papers
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TL;DR: In this article, the dependence of the nitrogen-vacancy (NV) optical properties on the magnetic field vector B has been studied in the high off-axis magnetic field regime where spin mixing alters the NV defect spin dynamics.
Abstract: Magnetometry and magnetic imaging with nitrogen–vacancy (NV) defects in diamond rely on the optical detection of electron spin resonance (ESR). However, this technique is inherently limited to magnetic fields that are weak enough to avoid electron spin mixing. Here, we focus on the high off-axis magnetic field regime where spin mixing alters the NV defect spin dynamics. We first study, in a quantitative manner, the dependence of the NV defect optical properties on the magnetic field vector B. Magnetic-field-dependent time-resolved photoluminescence (PL) measurements are compared to a seven-level model of the NV defect that accounts for field-induced spin mixing. The model reproduces decreases in (i) ESR contrast, (ii) PL intensity and (iii) excited level lifetime with an increasing off-axis magnetic field. We next demonstrate that these effects can be used to perform all-optical imaging of the magnetic field component |B⊥| orthogonal on the NV defect axis. Using a scanning NV defect microscope, we map the stray field of a magnetic hard disc through both PL and fluorescence lifetime imaging. This all-optical method for high magnetic field imaging at the nanoscale might be of interest in the field of nanomagnetism, where samples producing fields in excess of several tens of milliteslas are typically found.
304 citations
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TL;DR: It is shown that nanodiamonds enter cells mainly by endocytosis, and converging data indicate that it is clathrin-mediated, and the results pave the way for the use of photoluminescent nanod diamonds in targeted intracellular labeling or biomolecule delivery.
Abstract: Diamond nanoparticles (nanodiamonds) have been recently proposed as new labels for cellular imaging. For small nanodiamonds (size <40 nm), resonant laser scattering and Raman scattering cross sections are too small to allow single nanoparticle observation. Nanodiamonds can, however, be rendered photoluminescent with a perfect photostability at room temperature. Such a remarkable property allows easier single-particle tracking over long time scales. In this work, we use photoluminescent nanodiamonds of size <50 nm for intracellular labeling and investigate the mechanism of their uptake by living cells. By blocking selectively different uptake processes, we show that nanodiamonds enter cells mainly by endocytosis, and converging data indicate that it is clathrin-mediated. We also examine nanodiamond intracellular localization in endocytic vesicles using immunofluorescence and transmission electron microscopy. We find a high degree of colocalization between vesicles and the biggest nanoparticles or aggregate...
292 citations
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TL;DR: Raltegravir is a potent inhibitor of human immunodeficiency virus (HIV) integrase and is clinically effective against viruses resistant to other classes of antiretroviral agents, however, it can select mutations in the HIV integrase gene that led to strong impairment of enzymes in vitro in the absence of ralteGravir.
Abstract: Raltegravir (MK-0518) is a potent inhibitor of human immunodeficiency virus (HIV) integrase and is clinically effective against viruses resistant to other classes of antiretroviral agents. However, it can select mutations in the HIV integrase gene. Nine heavily pretreated patients who received salvage therapy including raltegravir and who subsequently developed virological failure under raltegravir therapy were studied. For each patient, the sequences of the integrase-coding region were determined and compared to that at the beginning of the treatment. Four different mutation profiles were identified in these nine patients: E92Q, G140S Q148H, N155H, and E157Q mutations. For four patients, each harboring a different profile, the wild-type and mutated integrases were produced, purified, and assayed in vitro. All the mutations identified altered the activities of integrase protein: both 3′ processing and strand transfer activities were moderately affected in the E92Q mutant; strand transfer was markedly impaired in the N155H mutant; both activities were strongly impaired in the G140S Q148H mutant; and the E157Q mutant was almost completely inactive. The sensitivities of wild-type and mutant integrases to raltegravir were compared. The E92Q and G140S Q148H profiles were each associated with a 7- to 8-fold decrease in sensitivity, and the N155H mutant was more than 14-fold less sensitive to raltegravir. At least four genetic profiles (E92Q, G140S Q148H, N155H, and E157Q) can be associated with in vivo treatment failure and resistance to raltegravir. These mutations led to strong impairment of enzymes in vitro in the absence of raltegravir: strand transfer activity was affected, and in some cases 3′ processing was also impaired.
290 citations
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TL;DR: The authors constructed new series for common native language and common spoken language for 195 countries, which they used together with series for Common official language and linguistic proximity in order to draw inferences about the aggregate impact of all linguistic factors on bilateral trade, the separate role of ease of communication as distinct from ethnicity and trust, and the contribution of translation and interpreters to ease of communications.
284 citations
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TL;DR: In this paper, a comparative study of two different electromechanical systems is presented in order to conceive autonomous portable generators capable of harvesting human mechanical energy, and the analytical models described in this paper present a high similarity and a duality in signal levels, adapted load and optimal working frequency, the two latters corresponding to the maximal electrical power generated.
Abstract: This paper presents the comparative study of two different electromechanical systems, in order to conceive autonomous portable generators capable of harvesting human mechanical energy. The first one is an electromagnetic system, made of a magnet in translation within a coil. The second one is a piezoelectric system, which is a PZT ceramic bar, polarised longitudinally, embedded at one end and constrained at the other end. The analytical models described in this paper present a high similarity and a duality in signal levels, adapted load and optimal working frequency, the two latters corresponding to the maximal electrical power generated.
273 citations
Authors
Showing all 2722 results
Name | H-index | Papers | Citations |
---|---|---|---|
Shi Xue Dou | 122 | 2028 | 74031 |
Olivier Hermine | 111 | 1026 | 43779 |
John R. Reynolds | 105 | 607 | 50027 |
Shaul Mukamel | 95 | 1030 | 40478 |
Tomás Torres | 88 | 625 | 28223 |
Ifor D. W. Samuel | 74 | 605 | 23151 |
Serge Abiteboul | 73 | 278 | 24576 |
Stéphane Roux | 68 | 627 | 19123 |
Zeger Debyser | 67 | 404 | 16531 |
Louis Nadjo | 64 | 264 | 12596 |
Praveen K. Thallapally | 64 | 190 | 12110 |
Andrew Travers | 63 | 193 | 13537 |
Shoji Takeuchi | 63 | 692 | 14704 |
Bineta Keita | 63 | 274 | 12053 |
Yves Mély | 62 | 368 | 13478 |