Laboratory experiments on multipolar vortices in a rotating fluid

The instability properties of isolated monopolar vortices have been investigated experimentally and the corresponding multipolar quasisteady states have been compared with semianalytical vorticity-distributed solutions to the Euler equations in two dimensions. A novel experimental technique was introduced to generate unstable monopolar vortices whose nonlinear evolution resulted in the formation of multipolar vortices. Dye-visualization and particle imaging techniques revealed the existence of tripolar, quadrupolar, and pentapolar vortices. Also evidence was found of the onset of hexapolar and heptapolar vortices. The observed multipolar vortices were found to be unstable and generally broke up into multipolar vortices of lesser complexity. The characteristic flow properties of the quadrupolar vortex were in close agreement with the semianalytical model solutions. Higher-order multipolar vortices were observed to be susceptible to strong inertial oscillations. © 2010 American Institute of Physic

The IS_MIRRI21 H2020 Project: Implementing the MIRRI-ERIC

The IS_MIRRI21 project running from 2020-2023 aims to implement the Microbial Resource Research Infrastructure (MIRRI) and secure its long-term sustainability. The mission of MIRRI is to serve Bioscience and Bioindustry by providing (a) a broad range of high-quality biological resources and associated data, (b) long-term sustainability of microbial biodiversity, and (c) knowledge and professional development. This mission will be achieved by offering users from academia, governmental laboratories and the private sector access to a portfolio of microbial Biological Resource Centres´ (mBRCs), services, expertise, education and training build-up and synergistically on the top of mBRCs proficiencies. To accelerate innovative research processes in life sciences and biotechnology using microorganisms, or their derivatives, IS_MIRRI21 has set up MIRRIs single-entry point portal to promote its services, resources, expertise and knowledge transfer activities, as well as to provide access to partners´ resource associated data made interoperable for data searching and data mining. The continuously increasing knowledge will be transferred to users via expert clusters (e.g., for legal framework, for biosecurity, to support training and education programs, information and cut edge technology, etc.). It will promote cross-disciplinary and innovative solutions (industry and academic) research collaboration through the transnational access offer in different microbial topics defined in pipeline services. With this project, MIRRI has become an ERIC in June 2022, and is a Landmark in the Health & Food domain of the European Strategy Forum on Research Infrastructures (ESFRI) Roadmap. It is still working to consolidate its operation and enlarge the membership and European coverage and beyond.info:eu-repo/semantics/publishedVersio

In vitro and in vivo evaluation of superparamagnetic iron oxide nanoparticles coated by bisphosphonates: the effects of electrical charge and molecule length.

Physicochemical coating properties are often considered to be determining factors for in vivo characteristics of superparamagnetic iron oxide nanoparticles, used as contrast agent in Magnetic Resonance Imaging (MRI). To investigate the electrical charge (modified by zero, one or two ammonium groups) and the molecule length (3, 5 or 7 methylene chains) effects of bisphosphonate-type coatings, we assessed the complement activation, in vivo plasma and tissue relaxation time alterations of intravenously injected small iron oxide nanoparticles (<25 nm) on male healthy Wistar rats. The presence of ammonium groups induces a weak activation of the complement whatever the size and the concentration of particles, whereas hydroxyethylenebisphosphonate (HEBP)-coated particles are poor complement activators only at the lowest concentration. In vivo, HEBP-coated nanoparticles have the greatest prolonged relaxation time effects, despite their higher negative electrical charge, contrary to two ammonium bearing coatings. No significant differences were observed between mono-ammonium molecular coatings

Divorticity and Dihelicity In Two-Dimensional Hydrodynamics

A framework is developed based on the concepts of {\it divorticity} ${\textbf B}$(\equiv\nabla\times\bfo, \bfo being the vorticity) and \textit{dihelicity} g \lp \equiv\bfv\cdot\textbf{B}\rp for discussing the theoretical structure underlying two-dimensional (2D) hydrodynamics. This formulation leads to the global and Lagrange invariants that could impose significant constraints on the evolution of divorticity lines in 2D hydrodynamics

Development of Understanding of The Interaction between Localized deformation and SCC of Austenitic Stainless Steels Exposed to Primary Environment

International audienceUnderstanding and quantification of interactions between localized deformation in materials and environmental-assisted cracking (EAC) could play an important role in maintaining the integrity of LWR components. Thus, a detailed understanding of strain localization during plastic deformation and of the underlying mechanisms is of great importance for the manufacturing and design of materials exposed to the environment of the primary circuit of PWRs. Thus, the crystal plasticity law of a 304L austenitic stainless steel has been identified, in order to quantify the effect of a change of strain path on the strain localization and increase the understanding of the contribution of the strain hardening and the strain incompatibilities on the mechanisms of initiation of SCC. Pre-deformation of the specimens used for SCC tests was evaluated using image correlation. Constant elongation rate tests and constant elongation tests were conducted for different levels of pre-deformations (0.07 < < 0.18). Examinations indicated the severe and deleterious effect of the strain localization due to a change of strain path on intergranular SCC susceptibility. Intergranular cracks initiated systematically in the low-deformed areas, where limited deformation (less than 1%) occurred during the exposure to the environment, and where high stress levels due to strain incompatibilities are expected

Impact of infection status and cyclosporine on voriconazole pharmacokinetics in an experimental model of cerebral scedosporiosis

Cerebral Scedosporium infections usually occur in lung transplant recipients as well as in immunocompetent patients in the context of near-drowning. Voriconazole is the first-line treatment. The diffusion of voriconazole through the blood-brain barriers in the context of cerebral infection and cyclosporine administration is crucial and remains a matter of debate. To address this issue, the pharmacokinetics of voriconazole were assessed in the plasma, cerebrospinal fluid (CSF), and brain, in an experimental model of cerebral scedosporiosis in rats receiving or not cyclosporine. A single dose of voriconazole (30 mg/kg, i.v.) was administrated to six groups of rats randomized according to the infection status and the cyclosporine dosing regimen (no cyclosporine, a single dose or three doses 15 mg/kg each). Voriconazole concentrations in plasma, CSF, and brain samples were quantified using UPLC-MS/MS and HPLC-UV methods and documented up to 48 hours after administration. Pharmacokinetic parameters were estimated using a non-compartmental approach. Voriconazole pharmacokinetic profiles were similar for plasma, CSF, and the brain in all groups studied. Voriconazole Cmax and AUC0=&gt;48h were significantly higher in the plasma than in the CSF (CSF/plasma ratio, median [range] = 0.5 [0.39-0.55] for AUC0=&gt;48h and 0.47 [0.35 and 0.75] for Cmax). Cyclosporine administration was significantly associated with an increase in voriconazole exposure in the plasma, CSF, and brain. In the plasma but not in the brain, an interaction between the infection and cyclosporine administration reduced the positive impact of cyclosporine on voriconazole exposure. Together these results emphasize the impact of cyclosporine on the brain voriconazole exposure

In vitro and in vivo behaviour of paclitaxel loaded lipid nanocapsules

International audienc

Statistics of an Unstable Barotropic Jet from a Cumulant Expansion

Low-order equal-time statistics of a barotropic flow on a rotating sphere are investigated. The flow is driven by linear relaxation toward an unstable zonal jet. For relatively short relaxation times, the flow is dominated by critical-layer waves. For sufficiently long relaxation times, the flow is turbulent. Statistics obtained from a second-order cumulant expansion are compared to those accumulated in direct numerical simulations, revealing the strengths and limitations of the expansion for different relaxation times.Comment: 23 pages, 8 figures. Version to appear in J. Atmos. Sc

Vorticity statistics in the two-dimensional enstrophy cascade

We report the first extensive experimental observation of the two-dimensional enstrophy cascade, along with the determination of the high order vorticity statistics. The energy spectra we obtain are remarkably close to the Kraichnan Batchelor expectation. The distributions of the vorticity increments, in the inertial range, deviate only little from gaussianity and the corresponding structure functions exponents are indistinguishable from zero. It is thus shown that there is no sizeable small scale intermittency in the enstrophy cascade, in agreement with recent theoretical analyses.Comment: 5 pages, 7 Figure