Search results for "40"
showing 10 items of 17345 documents
Artificial cartilage bio-matrix formed of hyaluronic acid and Mg2+-polyphosphate.
2016
Here we show that inorganic polyphosphate (polyP), a polyanionic metabolic regulator consisting of multiple phosphate residues linked by energy-rich phosphoanhydride bonds, is present in the synovial fluid. In a biomimetic approach, to enhance cartilage synthesis and regeneration, we prepared amorphous polyP microparticles with Mg2+ as counterions. The particles were characterised by X-ray diffraction (XRD), energy-dispersive X-ray (EDX) and Fourier transformed infrared spectroscopic (FTIR) analyses. Similar particles were obtained after addition of Mg2+ ions to a solution containing hyaluronic acid, as a major component of the synovial fluid, and soluble Na-polyP. The viscous paste-like ma…
Three-dimensional bimetallic octacyanidometalates $[M^{IV}{(\mu-CN)_{4}Mn^{II}(H_{2}O)_2}_2 \cdot 4H_{2}O]_{n}$ (M=Nb,Mo,W) : synthesis, single-cryst…
2008
Abstract We report the synthesis, the single-crystal X-ray crystallographic structures and the magnetic properties of three new isostructural cyanido-bridged networks: [M IV {(μ-CN) 4 Mn II (H 2 O) 2 } 2 ·4H 2 O] n [M IV = Nb IV ( 1 ), Mo IV ( 2 ), W IV ( 3 )]. For compound 1 , the magnetic properties reveal a ferrimagnetic phase below 50 K. In contrast, compounds 2 and 3 show a paramagnetic behaviour with no magnetic ordering down to 2 K. The only electronic difference between the two kinds of compounds is the presence of two paired electrons on Mo IV ( 2 ) and W IV ( 3 ) (d 2 electronic configuration, S = 0) with no possible exchange interactions with Mn II ions (d 5 electronic configur…
Systematic Study of a Library of PDMAEMA-Based, Superparamagnetic Nano-Stars for the Transfection of CHO-K1 Cells.
2017
The introduction of the DNA into mammalian cells remains a challenge in gene delivery, particularly in vivo. Viral vectors are unmatched in their efficiency for gene delivery, but may trigger immune responses and cause severe side-reactions. Non-viral vectors are much less efficient. Recently, our group has suggested that a star-shaped structure improves and even transforms the gene delivery capability of synthetic polycations. In this contribution, this effect was systematically studied using a library of highly homogeneous, paramagnetic nano-star polycations with varied arm lengths and grafting densities. Gene delivery was conducted in CHO-K1 cells, using a plasmid encoding a green fluore…
Immobilized Pd on magnetic nanoparticles bearing proline as a highly efficient and retrievable Suzuki–Miyaura catalyst in aqueous media
2015
A magnetically retrievable nanocatalyst was evaluated for amicrowave assisted Suzuki–Miyaura reaction in aqueous media.Excellent yields and conversions were obtained with low Pd loadings(down to 0.01 mol% Pd). It was stable up to 6 months in waterunder aerobic conditions and efficiency remained unaltered evenafter 7 repeated cycles. Refereed/Peer-reviewed
Folate targeted coated SPIONs as efficient tool for MRI
2017
The development of more sensitive diagnostic tools allowing an early-stage and highly efficient medical imaging of tumors remains a challenge. Magnetic nanoparticles seem to be the contrast agents with the highest potential, if properly constructed. Therefore, in this study, hybrid magnetic nanoarchitectures were developed using a new amphiphilic inulin-based graft copolymer (INU-LAPEG-FA) as coating material for 10-nm spinel iron oxide (magnetite, Fe3O4) superparamagnetic nanoparticles (SPION). Folic acid (FA) covalently linked to the coating copolymer in order to be exposed onto the nanoparticle surface was chosen as the targeting agent because folate receptors are upregulated in many can…
Chiral Magneto-Electrochemistry
2018
Magneto-electrochemistry (MEC) is a unique paradigm in science, where electrochemical experiments are carried out as a function of an applied magnetic field, creating a new horizon of potential scientific interest and technological applications. Over time, detailed understanding of this research domain was developed to identify and rationalize the possible effects exerted by a magnetic field on the various microscopic processes occurring in an electrochemical system. Notably, until a few years ago, the role of spin was not taken into account in the field of magneto-electrochemistry. Remarkably, recent experimental studies reveal that electron transmission through chiral molecules is spin se…
Spoken-Word Segmentation and Dyslexia
2002
We used magnetoencephalography to elucidate the cortical activation associated with the segmentation of spoken words in nonreading-impaired and dyslexic adults. The subjects listened to binaurally presented sentences where the sentence-ending words were either semantically appropriate or inappropriate to the preceding sentence context. Half of the inappropriate final words shared two or three initial phonemes with the highly expected semantically appropriate words. Two temporally and functionally distinct response patterns were detected in the superior temporal lobe. The first response peaked at approximately 100 msec in the supratemporal plane and showed no sensitivity to the semantic appr…
Motivic Pattern Extraction in Music, and Application to the Study of Tunisian Modal Music
2007
A new methodology for automated extraction of repeated patterns in time-series data is presented, aimed in particular at the analysis of musical sequences. The basic principles consists in a search for closed patterns in a multi-dimensional parametric space. It is shown that this basic mechanism needs to be articulated with a periodic pattern discovery system, implying therefore a strict chronological scanning of the time-series data. Thanks to this modelling global pattern filtering may be avoided and rich and highly pertinent results can be obtained. The modelling has been integrated in a collaborative pro ject between ethnomusicology, cognitive sciences and computer science, aimed at the…
Spontaneous Music-Evoked Autobiographical Memories in Individuals Experiencing Depression
2020
Listening to music often triggers strong memories of events from our past, which influence how we affectively experience music listening and can therefore contribute to music’s therapeutic capacity. The aim of this study was to examine the valence and content of spontaneous music-evoked autobiographical memories (MEAMs) in listeners with self-reported depression, who typically demonstrate negatively biased autobiographical memory. Eighteen depressed and 21 controls participated in a music-listening experiment where they listened to a personalized music stimulus, described their memories, and thereafter rated the valence of these memories and of their induced affect. Participants’ ratings w…
A Review of Biosensors for Non-Invasive Diabetes Monitoring and Screening in Human Exhaled Breath
2019
Exhaled breath acetone has been identified as a diabetes biomarker for non-invasive diagnosis. Its detection using biosensors features has many advantages over the conventional means. This paper reviews the recent literature on the detection of exhaled breath acetone and acetone vapor of diabetic interest. The biosensors have been classified based on their transduction methods. The performance characteristics of the biosensors have been explored for comparison. The future trends are also highlighted.