615 research outputs found
Novel applications of long-established histochemical techniques to study nanoparticle-cell interactions at transmission electron microscopy
Alcian blue staining has been used to visualise nanoparticles at transmission electron microscop
Neither backward masking of T2 nor task switching is necessary for the attentional blink
Identification of the second of two targets
(T1, T2, inserted in a stream of distractors) is impaired
when presented within 500 ms after the first (attentional
blink, AB). Barring a T1-T2 task-switch, it is thought
that T2 must be backward-masked to obtain an AB
(Giesbrecht & Di Lollo, Journal of Experimental Psychology:
Human Perception and Performance, 24, 1454-
1466, 1998). We tested the hypothesis that Giesbrecht &
Di Lollo's findings were vitiated by ceiling constraints
arising from either response scale (experiment 1) or data
limitations (experiment 2). In experiment 1, digitdistractors
were replaced with pseudoletters to increase
task difficulty, bringing performance below ceiling. An
AB occurred without backward masking of T2. In
experiment 2, a ceiling-free procedure estimated the
number of noise dots needed for 80% T2 identification.
An AB was revealed: fewer noise dots were required
during the AB period than outside it. Both outcomes
confirm that an AB can be obtained without either
masking of T2 or task switching
Hyaluronic acid-based nanocomplexes as novel drug-nanocarriers to treat myotonic dystrophy
Hyaluronic acid-based nanocomplexes have been developpend as novel drug-nanocarriers to treat myotonic dystroph
Thermal issues for the optical transition radiation screen for the ELI-NP compton gamma source
A high brightness electron LINAC is being built in the Compton Gamma Source at the ELI Nuclear Physics facility in Romania. To achieve the design luminosity, a train of 32 bunches, 16 ns spaced, with a nominal charge of 250 pC will collide with a laser beam in two interaction points. Electron beam spot size is measured with Optical Transition Radiation (OTR) profile monitors. In order to measure the beam properties, the OTR screens must sustain the thermal and mechanical stress due to the energy deposited by bunches. This paper is an ANSYS study of the issues due to the high energy transferred to the OTR screens. Thermal multicycle analysis will be shown; each analysis will be followed by a structural analysis in order to investigate the performance of the materia
Turbulent kinetic energy redistribution in a gravity current interacting with an emergent cylinder
Funding Information: AR and RF acknowledge the Portuguese Foundation for Science and Technology (FCT) for its financial support via the project PTDC/CTA-OHR/30561/2017 (WinTherface). MB acknowledges the Portuguese Foundation for Science and Technology (FCT-MCTES) for its financial support via the project UIDB/00667/2020 and UIDP/00667/2020 (UNIDEMI). CA acknowledges the Italian Ministry of University and Research (MUR) for funding the project 2022SAFKS4 . All Authors have read and approved the submitted manuscript. Publisher Copyright: © 2023 The AuthorsGravity currents are flows driven by density gradients between two or more contacting fluids and play a key role in nature and industrial environments via global ocean circulations, climate variability and the distribution of airborne pollutants. In the present work, we study, experimentally, the changes induced by an emergent vertical PVC cylinder on the mean and turbulent flow fields of an unsteady bottom-generated lock release gravity current. Tests were carried out, with and without the cylinder, in refractive index matching conditions and instantaneous velocities were acquired with a Particle Image Velocimetry system. The mean velocity field, Reynolds stresses and terms of turbulent kinetic energy (TKE) budget for the currents head were presented and discussed. The results show that the adverse pressure gradient generated by the cylinder induces a uniform deceleration of the current head. Hence, there are no appreciable differences on the spatial distribution of the mean velocities in the current head, compared to the undisturbed current. On the other hand, the changes on the turbulent flow field are remarkable. The total diffusion of TKE decays in the inner part of the head while becoming stronger at the interface between the two fluids, as the current approaches the cylinder. This is associated to an increase of the diffusion term due to pressure fluctuations, that acts against diffusion due to velocity fluctuations and contributes to disrupt the transport of TKE from the interface between the fluids and the inner part of the current. As a result, in the presence of an obstacle, Reynolds stresses are suppressed in the inner part of the current head and enhanced at the interface.publishersversionpublishe
LES validation of lock-exchange density currents interacting with an emergent bluff obstacle
Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Nature B.V.We address the capability of large eddy simulation (LES) to predict the physics of density currents interacting with bluff obstacles. Most density currents of interest in engineering and geophysical applications interact with obstacles or topographic features. Validating LES solutions in these contexts is crucial to establish it as a trusted tool. We thus propose a validation effort based on simple geometries that nonetheless pose challenges common to more complex systems, including boundary layer separation and convective instabilities. We focus on lock-exchange gravity currents in the slumping phase interacting with an emergent vertical circular cylinder. Our main investment was in ensuring that the comparison of experimental data and numerical results include, at least, the velocity and the density fields , and derived quantities (e.g., second order moments). Measurements of both density and velocity fields were performed in the side and plan views for cylinder Reynolds numbers, Red, in the range 1300 to 3475. It was found that the LES accurately predicts the temporal evolution of the current front position. The computed front velocity exhibits a maximum relative error less than 8%. A good agreement between the LES and the experimental size and shape of the current head, and billows was found. The overall features upstream the cylinder, including a reflected wave, adverse pressure gradient and backflow, and downstream the cylinder, including the backflow, wake and the formation of a new head are well reproduced by LES. The agreement between the LES and the experimental time-space evolution of current spanwise- and depth-averaged density contours and the instantaneous velocity fields are not affected by Red.publishersversionpublishe
Development of multifunctional lipid nanocapsules for the co-delivery of paclitaxel and CpG-ODN in the treatment of glioblastoma
In this work, multifunctional lipid nanocapsules (M-LNC) were designed to combine the activity of the cytotoxic drug paclitaxel (PTX) with the immunostimulant CpG. This nanosystem, consisting of modified lipid nanocapsules coated with a cationic polymeric shell composed of chitosan (CS), was able to allocate the hydrophobic drug PTX in the inner oily core, and to associate onto the surface the genetic material CpG. The CS-coated LNC (CS-LNC), showed a narrow size distribution with an average size of 70nm and a positive zeta potential (+25mV). They encapsulated PTX in a high amount (98%), and, due to the cationic surface charge, were able to adsorb CpG without losing stability. As a preliminary in vitro study, the apoptotic effect on GL261 glioma cells was investigated. The drug-loaded CS-LNC exhibited the ability to interact with glioma cells and induce an important apoptotic effect in comparison with blank systems. Finally, the M-LNC made of CS-LNC loaded with both CpG and PTX were tested in vivo, injected via convention enhanced delivery (CED) in GL261-glioma-bearing mice. The results showed that the overall survival of mice treated with the M-LNC was significantly increased in comparison with the control, Taxol(®), or the separated injection of PTX-loaded LNC and CpG. This effect was also confirmed by magnetic resonance imaging (MRI) which revealed the reduction of tumor growth in the animals treated with CpG and PTX-loaded M-LNC. All these findings suggested that the developed M-LNC could potentiate both CpG immunopotency and PTX antitumor activity by enhancing its delivery into the tumor microenvironment
Nanocarriers for neuromuscular diseases
Overview of the results obtained so far in the frame of a research on suitable nanocarriers for treating myotonic dystroph
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