Hinaut A.,Center dElaboration des Mateacute |
Lekhal K.,Center dElaboration des Mateacute |
Lekhal K.,Universiteacute |
Aivazian G.,Center dElaboration des Mateacute |
And 5 more authors.
Journal of Physical Chemistry C | Year: 2011
Molecular adsorption studies on atomically clean, well-defined surfaces of bulk insulators are still very scarce and have been restricted to a small number of molecules. In this study, the adsorption of 2,3,6,7,10,11- hexamethoxytriphenylene (HMTP) on KBr(001) was investigated by atomic force microscopy in noncontact mode (NC-AFM) under ultrahigh vacuum at room temperature from submonolayer to multilayer coverage. This molecule is the first member of a new family of molecules, designed and synthesized for adsorption studies on alkali halide surfaces. They were built around a flat aromatic triphenylene core equipped with peripheral polar groups to enhance the interaction of the molecule with the surface in order to limit molecular diffusion at room temperature. Constant-frequency-shift NC-AFM imaging established the following adsorption sequence: The molecules decorate the KBr steps before forming two-molecular-layerthick islands with a distorted hexagonal arrangement. At higher coverage, a second generation of much taller islands with the structure of the bulk HMTP crystal appears as a consequence of a dewetting transition, driven by the deformation energy accumulated in the first-generation islands during growth. High-resolution images obtained on top of these islands show submolecular contrast. These results will be useful in optimizing the next generation of molecules of this new family. © 2011 American Chemical Society.
El Sanharawi M.,Universiteacute |
Touchard E.,Eyevensys |
Benard R.,Eyevensys |
Bigey P.,Universiteacute |
And 6 more authors.
Gene Therapy | Year: 2013
Inhibition of vascular endothelial growth factor (VEGF) has become the standard of care for patients presenting with wet age-related macular degeneration. However, monthly intravitreal injections are required for optimal efficacy. We have previously shown that electroporation enabled ciliary muscle gene transfer results in sustained protein secretion into the vitreous for up to 9 months. Here, we evaluated the long-term efficacy of ciliary muscle gene transfer of three soluble VEGF receptor-1 (sFlt-1) variants in a rat model of laser-induced choroidal neovascularization (CNV). All three sFlt-1 variants significantly diminished vascular leakage and neovascularization as measured by fluorescein angiography (FA) and flatmount choroid at 3 weeks. FA and infracyanine angiography demonstrated that inhibition of CNV was maintained for up to 6 months after gene transfer of the two shortest sFlt-1 variants. Throughout, clinical efficacy was correlated with sustained VEGF neutralization in the ocular media. Interestingly, treatment with sFlt-1 induced a 50% downregulation of VEGF messenger RNA levels in the retinal pigment epithelium and the choroid. We demonstrate for the first time that non-viral gene transfer can achieve a long-term reduction of VEGF levels and efficacy in the treatment of CNV. Copy; 2013 Macmillan Publishers Limited. © 2013 Macmillan Publishers Limited.
Acute toxicity of a commercial glyphosate formulation on European sea bass juveniles (Dicentrarchus labrax L.): gene expressions of heme oxygenase-1 (ho-1), acetylcholinesterase (AChE) and aromatases (cyp19a and cyp19b)
Prevot-D'Alvise N.,Université |
Richard S.,Université |
Coupe S.,Université |
Bunet R.,Université |
Cellular and molecular biology (Noisy-le-Grand, France) | Year: 2013
Acute toxicity of Roundup, a commercial glyphosate--based herbicide, was evaluated in a teleost marine fish, the European sea bass, after 96 h of exposure. The LC50 96-h value of Roundup was 529 mg/L. Juveniles (Dicentrarchus labrax L.) were exposed to a sublethal concentration (35% of the LC50, i.e. 193 mg/L) of Roundup for 96-h. The study of heme oxygenase-1 (ho-1) gene expression was performed in four tissues (liver, gills, brain and gonads) and highlighted the disruption of antioxidant defence system. Results showed that ho-1 mRNA levels in liver and gills significantly decreased (p<0.001 and p<0.01 respectively) in fish exposed to 193 mg/L of Roundup, whereas in brain and gonads, ho-1 mRNA level was not altered. The analysis of acetylcholinesterase expression was used to evaluate the overall neurotoxicity of the herbicide and aromatase genes to assess the alteration of the endocrine system. Results showed that AChE and cyp19b gene transcriptions significantly increased (p<0.01) in brain of sea bass, whereas aromatase gene expression (cyp19a) in gonads was not significantly altered. Our results showed complex tissue-specific transcriptional responses after 96 h of exposure to a sublethal concentration. All these disruptions confirmed the deleterious effects of this glyphosate-based herbicide in a marine species.
Richman S.E.,University of Wyoming |
Richman S.E.,Universiteacute |
Lovvorn J.R.,Southern Illinois University Carbondale
Physiological and Biochemical Zoology | Year: 2011
For small aquatic endotherms, heat loss while floating on water can be a dominant energy cost, and requires accurate estimation in energetics models for different species. We measured resting metabolic rate (RMR) in air and on water for a small diving bird, the Cassin's auklet (Ptychoramphus aleuticus), and compared these results to published data for other diving birds of diverse taxa and sizes. For 8 Cassin's auklets (~165 g), the lower critical temperature was higher on water (21°C) than in air (16°C). Lowest values of RMR (W kg-1) averaged 19% higher on water (12.14±3.14 SD) than in air (10.22±1.43). At lower temperatures, RMR averaged 25% higher on water than in air, increasing with similar slope. RMR was higher on water than in air for alcids, cormorants, and small penguins but not for diving ducks, which appear exceptionally resistant to heat loss in water. Changes in RMR (W) with body mass either in air or on water were mostly linear over the 5- to 20-fold body mass ranges of alcids, diving ducks, and penguins, while cormorants showed no relationship of RMR with mass. The often large energetic effects of time spent floating on water can differ substantially among major taxa of diving birds, so that relevant estimates are critical to understanding their patterns of daily energy use. © 2011 by the University of Chicago.
Lopez T.,Higher Institute of Aeronautics and Space |
Massenot S.,Higher Institute of Aeronautics and Space |
Estribeau M.,Higher Institute of Aeronautics and Space |
Magnan P.,Higher Institute of Aeronautics and Space |
And 2 more authors.
Optics Express | Year: 2016
This paper deals with the integration of metallic and dielectric nanostructured planar lenses into a pixel from a silicon based CMOS image sensor, for a monochromatic application at 1:064μm. The first is a Plasmonic Lens, based on the phase delay through nanoslits, which has been found to be hardly compatible with current CMOS technology and exhibits a notable metallic absorption. The second is a dielectric Phase-Fresnel Lens integrated at the top of a pixel, it exhibits an Optical Efficiency (OE) improved by a few percent and an angle of view of 50°. The third one is a metallic diffractive lens integrated inside a pixel, which shows a better OE and an angle of view of 24°. The last two lenses exhibit a compatibility with a spectral band close to 1:064μm. © 2016 Optical Society of America.
Annual Review of Biochemistry | Year: 2014
Lipids are unevenly distributed within and between cell membranes, thus defining organelle identity. Such distribution relies on local metabolic branches and mechanisms that move lipids. These processes are regulated by feedback mechanisms that decipher topographical ormation in organelle membranes and then regulate lipid levels or flows. In the endoplasmic reticulum, the major lipid source, transcriptional regulators and enzymes sense changes in membrane features to modulate lipid production. At the Golgi apparatus, lipid-synthesizing, lipid-flippase, and lipid-Transport proteins (LTPs) collaborate to control lipid balance and distribution within the membrane to guarantee remodeling processes crucial for vesicular trafficking. Open questions exist regarding LTPs, which are thought to be lipid sensors that regulate lipid synthesis or carriers that transfer lipids between organelles across long distances or in contact sites. A novel model is that LTPs, by exchanging two different lipids, exploit one lipid gradient between two distinct membranes to build a second lipid gradient. Copyright © 2014 by Annual Reviews. All rights reserved.
Gonome H.,Tohoku University |
Baneshi M.,Tohoku University |
Vaillon R.,Universiteacute |
Okajima J.,Tohoku University |
And 2 more authors.
Journal of Thermal Science and Technology | Year: 2012
This study describes nanoparticle pigmented coatings used in controlling the radiative properties of surfaces exposed to sunlight. The effect of particle dispersed state to reflectance of the coating is discussed. As the dispersed particles, TiO 2 and Fe 2O 3 are used. From Raman spectral intensity measurements made on the coating, the dispersed state of particles was investigated. The spectral reflectance of the coating was measured by spectroscopy. The reflectivity of the coating is analyzed theoretically. In this calculation, the dispersed state is assumed to be monodispersed and homogeneous. Comparison between experimental and numerical results shows that the difference between the measured and calculated reflectance increases as the volume fraction increases. The maximum absolute error of reflectance is about 10% when the volume fraction is 0.05. In contrast, the maximum absolute error of reflectance is about 3% when the volume fraction is 0.01. The control of dispersed state affects the radiative properties of pigmented coatings. © 2012 by JSME.
Gustin J.,Universiteacute |
Bonfond B.,Universiteacute |
Grodent D.,Universiteacute |
Journal of Geophysical Research: Space Physics | Year: 2012
The STIS and ACS instruments onboard HST are widely used to study the giant planet's aurora. Several assumptions have to be made to convert the instrumental counts into meaningful physical values (type and bandwidth of the filters, definition of the physical units, etc...), but these may significantly differ from one author to another, which makes it difficult to compare the auroral characteristics published in different studies. We present a method to convert the counts obtained in representative ACS and STIS imaging modes/filters used by the auroral scientific community to brightness, precipitated power and radiated power in the ultraviolet (700-1800 Å). Since hydrocarbon absorption may considerably affect the observed auroral emission, the conversion factors are determined for several attenuation levels. Several properties of the auroral emission have been determined: the fraction of the H2 emission shortward and longward of the HLy-a line is 50.3% and 49.7% respectively, the contribution of HLy-a to the total unabsorbed auroral signal has been set to 9.1% and an input of 1mWm 2 produces 10 kR of H2 in the Lyman and Werner bands. A first application sets the order of magnitude of Saturn's auroral characteristics in the total UV bandwidth to a brightness of 10 kR and an emitted power of 2.8 GW. A second application uses published brightnesses of Europa's footprint to determine the current density associated with the Europa auroral spot: 0.21 and 0.045 mA m 2 assuming no hydrocarbon absorption and a color ratio of 2, respectively. Factors to extend the brightnesses observed with Cassini-UVIS to total H2 UV brightnesses are also provided. © 2012. American Geophysical Union.
PubMed | Université
Type: Comparative Study | Journal: Investigative ophthalmology & visual science | Year: 2012
To measure the pulsatile movement of neuroretinal tissue at the optic nerve head synchronous with the cardiac cycle.We used a noninvasive imaging device based on Fourier domain low-coherence interferometry to measure the pulsatile movements of the optic nerve head, peripapillary retina, and cornea with submicron accuracy along a line across the fundus. We also measured the change in the Axial Distance between the peripapillary Retina and the base of the optic disc Cup (ADRC) during the cardiac cycle. Twelve normal subjects and 20 subjects with open-angle glaucoma were tested.In normal subjects, the mean fundus pulsation amplitude (defined as the fundus movement minus the simultaneous corneal movement) were 13.0 2.5 m, 9.0 2.1 m, and 8.7 2.9 m at the base of the optic nerve head cup, the nasal peripapillary retina, and the temporal peripapillary retina, respectively, compared with 16.7 6.8 m, 17.3 10.9 m, and 12.7 6.2 m for the corresponding values in the glaucoma group (P = 0.26, P = 0.008, and P = 0.12, respectively). The mean changes in ADRC during the cardiac cycle in normal subjects were 10.7 2.1 m and 11.6 1.8 m for the nasal and temporal side of the optic disc, respectively, compared to 14.9 5.6 m and 14.0 4.9 m in glaucoma subjects (P = 0.03 and P = 0.10, respectively).There was an approximately 11-m pulsatile change in the ADRC in normal subjects, and on the nasal side of the disc, this amount was significantly greater in glaucoma patients.
PubMed | University of Poitiers and Université
Type: Journal Article | Journal: Cellular and molecular biology (Noisy-le-Grand, France) | Year: 2014
Spinal cord injuries (SCI) induce a loss of skeletal muscle mass and functional capacity. The muscle excitability and contractility depend on the plasma membrane potential, regulated by transmembrane ion gradients, and thus necessarily on the Na,K-ATPase activity. The aim of this work was to evaluate the consequences of a spinal cord transection (SCT) on the skeletal muscle Na,K-ATPase and the impact of collateral GlyceroPhosphoLipids enriched in DocosaHexaenoic Acid (GPL-DHA) administration. The Na,K-ATPase activity and membrane expression of Na,K-ATPase 1, 2 and 1 isoforms were assessed by K-stimulated paranitrophenyl phosphatase (pNPPase) measurements and Western Blotting, respectively. The results show that spinal cord transection increased significantly (p<0.05) Na,K-ATPase activity in muscle by 25% and decreased the amounts of 1 isoform and 2 isoform expressions by 50% (p<0.05) respectively compared to controls. The results also show that early injection of GPL-DHA after SCT decreases in membrane skeletal muscle the 1 and 2 isoforms expression but increases the membrane Na,K-ATPase activity. This treament partially restores the membrane expression of the 1 subunit of the Na,K-ATPase. These data suggest that the increase of 1 subunit expression is probably the main trigger to the membrane Na,K-ATPase activation following a trans-synaptic denervation.